diff --git a/.golangci.yml b/.golangci.yml
index bee10879c..1aeced02b 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -5,17 +5,21 @@ run:
 linters-settings:
   lll:
     line-length: 120
+  staticcheck:
+    checks:
+      - all
+      - '-SA1019' # it is okay to use math/rand at times
 
 linters:
   disable-all: true
   enable:
-  #  - errcheck
-  #  - ineffassign
-  #  - gas
+    - errcheck
+    - ineffassign
+    # - gas
     - gofmt
-  #  - gosimple
-  #  - govet
-  #  - lll
-  #  - unused
-  #  - staticcheck
+    - gosimple
+    - govet
+    - lll
+    - unused
+    - staticcheck
     - goimports
diff --git a/backup.go b/backup.go
index 9af409027..fcc8a1086 100644
--- a/backup.go
+++ b/backup.go
@@ -79,8 +79,7 @@ func (stream *Stream) Backup(w io.Writer, since uint64) (uint64, error) {
 			var valCopy []byte
 			if !item.IsDeletedOrExpired() {
 				// No need to copy value, if item is deleted or expired.
-				var err error
-				err = item.Value(func(val []byte) error {
+				err := item.Value(func(val []byte) error {
 					valCopy = a.Copy(val)
 					return nil
 				})
diff --git a/badger/cmd/flatten.go b/badger/cmd/flatten.go
index 66095520e..7fbfc6386 100644
--- a/badger/cmd/flatten.go
+++ b/badger/cmd/flatten.go
@@ -67,7 +67,7 @@ func flatten(cmd *cobra.Command, args []string) error {
 	if err != nil {
 		return err
 	}
-	if fo.compressionType < 0 || fo.compressionType > 2 {
+	if fo.compressionType > 2 {
 		return errors.Errorf(
 			"compression value must be one of 0 (disabled), 1 (Snappy), or 2 (ZSTD)")
 	}
diff --git a/badger/cmd/rotate_test.go b/badger/cmd/rotate_test.go
index 54519bbef..b718f0b7a 100644
--- a/badger/cmd/rotate_test.go
+++ b/badger/cmd/rotate_test.go
@@ -108,9 +108,9 @@ func TestRotatePlainTextToEncrypted(t *testing.T) {
 	db, err := badger.Open(opts)
 	require.NoError(t, err)
 
-	db.Update(func(txn *badger.Txn) error {
+	require.NoError(t, db.Update(func(txn *badger.Txn) error {
 		return txn.Set([]byte("foo"), []byte("bar"))
-	})
+	}))
 
 	require.NoError(t, db.Close())
 
@@ -140,7 +140,7 @@ func TestRotatePlainTextToEncrypted(t *testing.T) {
 	db, err = badger.Open(opts)
 	require.NoError(t, err)
 
-	db.View(func(txn *badger.Txn) error {
+	require.NoError(t, db.View(func(txn *badger.Txn) error {
 		iopt := badger.DefaultIteratorOptions
 		it := txn.NewIterator(iopt)
 		defer it.Close()
@@ -150,6 +150,6 @@ func TestRotatePlainTextToEncrypted(t *testing.T) {
 		}
 		require.Equal(t, 1, count)
 		return nil
-	})
+	}))
 	require.NoError(t, db.Close())
 }
diff --git a/badger/cmd/stream.go b/badger/cmd/stream.go
index 58e6c4535..a7d64f15f 100644
--- a/badger/cmd/stream.go
+++ b/badger/cmd/stream.go
@@ -85,7 +85,7 @@ func stream(cmd *cobra.Command, args []string) error {
 		WithEncryptionKey(encKey)
 
 	// Options for output DB.
-	if so.compressionType < 0 || so.compressionType > 2 {
+	if so.compressionType > 2 {
 		return errors.Errorf(
 			"compression value must be one of 0 (disabled), 1 (Snappy), or 2 (ZSTD)")
 	}
@@ -126,6 +126,7 @@ func stream(cmd *cobra.Command, args []string) error {
 		f, err := os.OpenFile(so.outFile, os.O_RDWR|os.O_CREATE, 0666)
 		y.Check(err)
 		_, err = stream.Backup(f, 0)
+		y.Check(err)
 	}
 	fmt.Println("Done.")
 	return err
diff --git a/badger/cmd/write_bench.go b/badger/cmd/write_bench.go
index b1865e1b1..d45f82c4e 100644
--- a/badger/cmd/write_bench.go
+++ b/badger/cmd/write_bench.go
@@ -314,7 +314,7 @@ func writeBench(cmd *cobra.Command, args []string) error {
 	}
 
 	c.SignalAndWait()
-	fmt.Printf(db.LevelsToString())
+	fmt.Println(db.LevelsToString())
 	return err
 }
 
@@ -401,7 +401,7 @@ func reportStats(c *z.Closer, db *badger.DB) {
 				humanize.IBytes(uint64(z.NumAllocBytes())))
 
 			if count%10 == 0 {
-				fmt.Printf(db.LevelsToString())
+				fmt.Println(db.LevelsToString())
 			}
 		}
 	}
diff --git a/db.go b/db.go
index 3e98be4d0..d4f1e06ae 100644
--- a/db.go
+++ b/db.go
@@ -49,10 +49,6 @@ var (
 	bannedNsKey  = []byte("!badger!banned") // For storing the banned namespaces.
 )
 
-const (
-	maxNumSplits = 128
-)
-
 type closers struct {
 	updateSize  *z.Closer
 	compactors  *z.Closer
@@ -1872,7 +1868,10 @@ func (db *DB) Subscribe(ctx context.Context, cb func(kv *KVList) error, matches
 	}
 
 	c := z.NewCloser(1)
-	s := db.pub.newSubscriber(c, matches)
+	s, err := db.pub.newSubscriber(c, matches)
+	if err != nil {
+		return y.Wrapf(err, "while creating a new subscriber")
+	}
 	slurp := func(batch *pb.KVList) error {
 		for {
 			select {
@@ -1926,11 +1925,6 @@ func (db *DB) Subscribe(ctx context.Context, cb func(kv *KVList) error, matches
 	}
 }
 
-// shouldEncrypt returns bool, which tells whether to encrypt or not.
-func (db *DB) shouldEncrypt() bool {
-	return len(db.opt.EncryptionKey) > 0
-}
-
 func (db *DB) syncDir(dir string) error {
 	if db.opt.InMemory {
 		return nil
@@ -1971,7 +1965,7 @@ func (db *DB) StreamDB(outOptions Options) error {
 	defer outDB.Close()
 	writer := outDB.NewStreamWriter()
 	if err := writer.Prepare(); err != nil {
-		y.Wrapf(err, "cannot create stream writer in out DB at %s", outDir)
+		return y.Wrapf(err, "cannot create stream writer in out DB at %s", outDir)
 	}
 
 	// Stream contents of DB to the output DB.
diff --git a/db2_test.go b/db2_test.go
index 6cb88aa12..a6e184e6b 100644
--- a/db2_test.go
+++ b/db2_test.go
@@ -883,7 +883,7 @@ func TestMaxVersion(t *testing.T) {
 		rand.Read(k)
 		// Create multiple version of the same key.
 		for i := 1; i <= N; i++ {
-			wb.SetEntryAt(&Entry{Key: k}, uint64(i))
+			require.NoError(t, wb.SetEntryAt(&Entry{Key: k}, uint64(i)))
 		}
 		require.NoError(t, wb.Flush())
 
@@ -906,7 +906,7 @@ func TestMaxVersion(t *testing.T) {
 
 		// This will create commits from 1 to N.
 		for i := 1; i <= N; i++ {
-			wb.SetEntryAt(&Entry{Key: []byte(fmt.Sprintf("%d", i))}, uint64(i))
+			require.NoError(t, wb.SetEntryAt(&Entry{Key: []byte(fmt.Sprintf("%d", i))}, uint64(i)))
 		}
 		require.NoError(t, wb.Flush())
 
@@ -1001,12 +1001,12 @@ func TestKeyCount(t *testing.T) {
 
 		write := func(kvs *pb.KVList) error {
 			buf := z.NewBuffer(1<<20, "test")
-			defer buf.Release()
+			defer func() { require.NoError(t, buf.Release()) }()
 
 			for _, kv := range kvs.Kv {
 				KVToBuffer(kv, buf)
 			}
-			writer.Write(buf)
+			require.NoError(t, writer.Write(buf))
 			return nil
 		}
 
diff --git a/db_test.go b/db_test.go
index 0535adcb2..19d81c5ff 100644
--- a/db_test.go
+++ b/db_test.go
@@ -610,7 +610,7 @@ func TestGetMore(t *testing.T) {
 			}
 			require.NoError(t, txn.Commit())
 		}
-		db.validate()
+		require.NoError(t, db.validate())
 		for i := 0; i < n; i++ {
 			if (i % 10000) == 0 {
 				// Display some progress. Right now, it's not very fast with no caching.
@@ -643,7 +643,7 @@ func TestExistsMore(t *testing.T) {
 			}
 			require.NoError(t, txn.Commit())
 		}
-		db.validate()
+		require.NoError(t, db.validate())
 
 		for i := 0; i < n; i++ {
 			if (i % 1000) == 0 {
@@ -673,7 +673,7 @@ func TestExistsMore(t *testing.T) {
 			}
 			require.NoError(t, txn.Commit())
 		}
-		db.validate()
+		require.NoError(t, db.validate())
 		for i := 0; i < n; i++ {
 			if (i % 10000) == 0 {
 				// Display some progress. Right now, it's not very fast with no caching.
@@ -1231,7 +1231,7 @@ func TestDiscardVersionsBelow(t *testing.T) {
 		opts.PrefetchValues = false
 
 		// Verify that there are 4 versions, and record 3rd version (2nd from top in iteration)
-		db.View(func(txn *Txn) error {
+		require.NoError(t, db.View(func(txn *Txn) error {
 			it := txn.NewIterator(opts)
 			defer it.Close()
 			var count int
@@ -1245,7 +1245,7 @@ func TestDiscardVersionsBelow(t *testing.T) {
 			}
 			require.Equal(t, 4, count)
 			return nil
-		})
+		}))
 
 		// Set new version and discard older ones.
 		err := db.Update(func(txn *Txn) error {
@@ -1255,7 +1255,7 @@ func TestDiscardVersionsBelow(t *testing.T) {
 
 		// Verify that there are only 2 versions left, and versions
 		// below ts have been deleted.
-		db.View(func(txn *Txn) error {
+		require.NoError(t, db.View(func(txn *Txn) error {
 			it := txn.NewIterator(opts)
 			defer it.Close()
 			var count int
@@ -1269,7 +1269,7 @@ func TestDiscardVersionsBelow(t *testing.T) {
 			}
 			require.Equal(t, 1, count)
 			return nil
-		})
+		}))
 	})
 }
 
@@ -1478,7 +1478,7 @@ func TestGetSetDeadlock(t *testing.T) {
 	timeout, done := time.After(10*time.Second), make(chan bool)
 
 	go func() {
-		db.Update(func(txn *Txn) error {
+		require.NoError(t, db.Update(func(txn *Txn) error {
 			item, err := txn.Get(key)
 			require.NoError(t, err)
 			err = item.Value(nil) // This take a RLock on file
@@ -1488,7 +1488,7 @@ func TestGetSetDeadlock(t *testing.T) {
 			require.NoError(t, txn.SetEntry(NewEntry(key, val)))
 			require.NoError(t, txn.SetEntry(NewEntry([]byte("key2"), val)))
 			return nil
-		})
+		}))
 		done <- true
 	}()
 
@@ -1818,9 +1818,9 @@ func TestMinReadTs(t *testing.T) {
 		db.orc.readMark.Done(uint64(20)) // Because we called readTs.
 
 		for i := 0; i < 10; i++ {
-			db.View(func(txn *Txn) error {
+			require.NoError(t, db.View(func(txn *Txn) error {
 				return nil
-			})
+			}))
 		}
 		time.Sleep(time.Millisecond)
 		require.Equal(t, uint64(20), db.orc.readMark.DoneUntil())
@@ -2089,7 +2089,7 @@ func TestVerifyChecksum(t *testing.T) {
 			st := 0
 
 			buf := z.NewBuffer(10<<20, "test")
-			defer buf.Release()
+			defer func() { require.NoError(t, buf.Release()) }()
 			for i := 0; i < 1000; i++ {
 				key := make([]byte, 8)
 				binary.BigEndian.PutUint64(key, uint64(i))
@@ -2153,12 +2153,12 @@ func TestWriteInemory(t *testing.T) {
 			item, err := txn.Get([]byte(fmt.Sprintf("key%d", j)))
 			require.NoError(t, err)
 			expected := []byte(fmt.Sprintf("val%d", j))
-			item.Value(func(val []byte) error {
+			require.NoError(t, item.Value(func(val []byte) error {
 				require.Equal(t, expected, val,
 					"Invalid value for key %q. expected: %q, actual: %q",
 					item.Key(), expected, val)
 				return nil
-			})
+			}))
 		}
 		return nil
 	})
@@ -2242,7 +2242,7 @@ func TestOpenDBReadOnly(t *testing.T) {
 	var count int
 	read := func() {
 		count = 0
-		db.View(func(txn *Txn) error {
+		require.NoError(t, db.View(func(txn *Txn) error {
 			it := txn.NewIterator(DefaultIteratorOptions)
 			defer it.Close()
 			for it.Rewind(); it.Valid(); it.Next() {
@@ -2254,7 +2254,7 @@ func TestOpenDBReadOnly(t *testing.T) {
 				count++
 			}
 			return nil
-		})
+		}))
 	}
 	read()
 	require.Equal(t, 10, count)
diff --git a/iterator_test.go b/iterator_test.go
index b54ec28d3..4eca18595 100644
--- a/iterator_test.go
+++ b/iterator_test.go
@@ -147,7 +147,7 @@ func TestIterateSinceTs(t *testing.T) {
 		iopt := DefaultIteratorOptions
 		iopt.SinceTs = sinceTs
 
-		db.View(func(txn *Txn) error {
+		require.NoError(t, db.View(func(txn *Txn) error {
 			it := txn.NewIterator(iopt)
 			defer it.Close()
 
@@ -156,7 +156,7 @@ func TestIterateSinceTs(t *testing.T) {
 				require.GreaterOrEqual(t, i.Version(), sinceTs)
 			}
 			return nil
-		})
+		}))
 
 	})
 }
diff --git a/levels.go b/levels.go
index 8ddfae7a9..798b2f660 100644
--- a/levels.go
+++ b/levels.go
@@ -998,20 +998,14 @@ func containsPrefix(table *table.Table, prefix []byte) bool {
 		// In table iterator's Seek, we assume that key has version in last 8 bytes. We set
 		// version=0 (ts=math.MaxUint64), so that we don't skip the key prefixed with prefix.
 		ti.Seek(y.KeyWithTs(prefix, math.MaxUint64))
-		if bytes.HasPrefix(ti.Key(), prefix) {
-			return true
-		}
-		return false
+		return bytes.HasPrefix(ti.Key(), prefix)
 	}
 
 	if bytes.Compare(prefix, smallValue) > 0 &&
 		bytes.Compare(prefix, largeValue) < 0 {
 		// There may be a case when table contains [0x0000,...., 0xffff]. If we are searching for
 		// k=0x0011, we should not directly infer that k is present. It may not be present.
-		if !isPresent() {
-			return false
-		}
-		return true
+		return isPresent()
 	}
 
 	return false
@@ -1426,8 +1420,8 @@ func (s *levelsController) runCompactDef(id, l int, cd compactDef) (err error) {
 		cd.splits = append(cd.splits, keyRange{})
 	}
 
-	// Table should never be moved directly between levels, always be rewritten to allow discarding
-	// invalid versions.
+	// Table should never be moved directly between levels,
+	// always be rewritten to allow discarding invalid versions.
 
 	newTables, decr, err := s.compactBuildTables(l, cd)
 	if err != nil {
diff --git a/levels_test.go b/levels_test.go
index 5c4ec113c..1e4448837 100644
--- a/levels_test.go
+++ b/levels_test.go
@@ -131,7 +131,7 @@ func TestCheckOverlap(t *testing.T) {
 }
 
 func getAllAndCheck(t *testing.T, db *DB, expected []keyValVersion) {
-	db.View(func(txn *Txn) error {
+	require.NoError(t, db.View(func(txn *Txn) error {
 		opt := DefaultIteratorOptions
 		opt.AllVersions = true
 		opt.InternalAccess = true
@@ -157,8 +157,7 @@ func getAllAndCheck(t *testing.T, db *DB, expected []keyValVersion) {
 		}
 		require.Equal(t, len(expected), i, "keys examined should be equal to keys expected")
 		return nil
-	})
-
+	}))
 }
 
 func TestCompaction(t *testing.T) {
@@ -783,7 +782,7 @@ func TestL1Stall(t *testing.T) {
 		go func() {
 			tab := createEmptyTable(db)
 			require.NoError(t, db.lc.addLevel0Table(tab))
-			tab.DecrRef()
+			require.NoError(t, tab.DecrRef())
 			done <- true
 		}()
 		time.Sleep(time.Second)
@@ -792,7 +791,7 @@ func TestL1Stall(t *testing.T) {
 		// Drop two tables from Level 0 so that addLevel0Table can make progress. Earlier table
 		// count was 4 which is equal to L0 stall count.
 		toDrop := db.lc.levels[0].tables[:2]
-		decrRefs(toDrop)
+		require.NoError(t, decrRefs(toDrop))
 		db.lc.levels[0].tables = db.lc.levels[0].tables[2:]
 		db.lc.levels[0].Unlock()
 
@@ -849,7 +848,7 @@ func TestL0Stall(t *testing.T) {
 		go func() {
 			tab := createEmptyTable(db)
 			require.NoError(t, db.lc.addLevel0Table(tab))
-			tab.DecrRef()
+			require.NoError(t, tab.DecrRef())
 			done <- true
 		}()
 		// Let it stall for a second.
@@ -1024,7 +1023,7 @@ func TestKeyVersions(t *testing.T) {
 			runBadgerTest(t, &inMemoryOpt, func(t *testing.T, db *DB) {
 				writer := db.newWriteBatch(false)
 				for i := 0; i < 10; i++ {
-					writer.Set([]byte(fmt.Sprintf("%05d", i)), []byte("foo"))
+					require.NoError(t, writer.Set([]byte(fmt.Sprintf("%05d", i)), []byte("foo")))
 				}
 				require.NoError(t, writer.Flush())
 				require.Equal(t, 2, len(db.Ranges(nil, 10000)))
@@ -1034,7 +1033,7 @@ func TestKeyVersions(t *testing.T) {
 			runBadgerTest(t, &inMemoryOpt, func(t *testing.T, db *DB) {
 				writer := db.newWriteBatch(false)
 				for i := 0; i < 100000; i++ {
-					writer.Set([]byte(fmt.Sprintf("%05d", i)), []byte("foo"))
+					require.NoError(t, writer.Set([]byte(fmt.Sprintf("%05d", i)), []byte("foo")))
 				}
 				require.NoError(t, writer.Flush())
 				require.Equal(t, 11, len(db.Ranges(nil, 10000)))
@@ -1044,7 +1043,7 @@ func TestKeyVersions(t *testing.T) {
 			runBadgerTest(t, &inMemoryOpt, func(t *testing.T, db *DB) {
 				writer := db.newWriteBatch(false)
 				for i := 0; i < 10000; i++ {
-					writer.Set([]byte(fmt.Sprintf("%05d", i)), []byte("foo"))
+					require.NoError(t, writer.Set([]byte(fmt.Sprintf("%05d", i)), []byte("foo")))
 				}
 				require.NoError(t, writer.Flush())
 				require.Equal(t, 1, len(db.Ranges([]byte("a"), 10000)))
@@ -1151,7 +1150,7 @@ func TestTableContainsPrefix(t *testing.T) {
 	}
 
 	tbl := buildTable([]string{"key1", "key3", "key31", "key32", "key4"})
-	defer tbl.DecrRef()
+	defer func() { require.NoError(t, tbl.DecrRef()) }()
 
 	require.True(t, containsPrefix(tbl, []byte("key")))
 	require.True(t, containsPrefix(tbl, []byte("key1")))
diff --git a/managed_db_test.go b/managed_db_test.go
index 1c7e0e3c0..8b9dedea5 100644
--- a/managed_db_test.go
+++ b/managed_db_test.go
@@ -280,7 +280,7 @@ func TestDropReadOnly(t *testing.T) {
 		require.Equal(t, err, ErrWindowsNotSupported)
 	} else {
 		require.NoError(t, err)
-		require.Panics(t, func() { db2.DropAll() })
+		require.Panics(t, func() { _ = db2.DropAll() })
 		require.NoError(t, db2.Close())
 	}
 }
@@ -527,7 +527,7 @@ func TestDropPrefixReadOnly(t *testing.T) {
 		require.Equal(t, err, ErrWindowsNotSupported)
 	} else {
 		require.NoError(t, err)
-		require.Panics(t, func() { db2.DropPrefix([]byte("key0")) })
+		require.Panics(t, func() { _ = db2.DropPrefix([]byte("key0")) })
 		require.NoError(t, db2.Close())
 	}
 }
diff --git a/manifest_test.go b/manifest_test.go
index 528029c22..b445ca048 100644
--- a/manifest_test.go
+++ b/manifest_test.go
@@ -17,7 +17,6 @@
 package badger
 
 import (
-	"context"
 	"fmt"
 	"io/ioutil"
 	"math/rand"
@@ -29,9 +28,7 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/require"
-	otrace "go.opencensus.io/trace"
 
-	"github.com/dgraph-io/badger/v3/options"
 	"github.com/dgraph-io/badger/v3/pb"
 	"github.com/dgraph-io/badger/v3/table"
 	"github.com/dgraph-io/badger/v3/y"
@@ -55,7 +52,7 @@ func TestManifestBasic(t *testing.T) {
 			txnSet(t, kv, k, k, 0x00)
 		}
 		txnSet(t, kv, []byte("testkey"), []byte("testval"), 0x05)
-		kv.validate()
+		require.NoError(t, kv.validate())
 		require.NoError(t, kv.Close())
 	}
 
@@ -115,17 +112,6 @@ func key(prefix string, i int) string {
 	return prefix + fmt.Sprintf("%04d", i)
 }
 
-func buildTestTable(t *testing.T, prefix string, n int, opts table.Options) *table.Table {
-	y.AssertTrue(n <= 10000)
-	keyValues := make([][]string, n)
-	for i := 0; i < n; i++ {
-		k := key(prefix, i)
-		v := fmt.Sprintf("%d", i)
-		keyValues[i] = []string{k, v}
-	}
-	return buildTable(t, keyValues, opts)
-}
-
 // TODO - Move these to somewhere where table package can also use it.
 // keyValues is n by 2 where n is number of pairs.
 func buildTable(t *testing.T, keyValues [][]string, bopts table.Options) *table.Table {
@@ -158,58 +144,6 @@ func buildTable(t *testing.T, keyValues [][]string, bopts table.Options) *table.
 	return tbl
 }
 
-func TestOverlappingKeyRangeError(t *testing.T) {
-	dir, err := ioutil.TempDir("", "badger-test")
-	require.NoError(t, err)
-	defer removeDir(dir)
-	kv, err := Open(DefaultOptions(dir))
-	require.NoError(t, err)
-	defer kv.Close()
-
-	lh0 := newLevelHandler(kv, 0)
-	lh1 := newLevelHandler(kv, 1)
-	opts := table.Options{ChkMode: options.OnTableAndBlockRead}
-	t1 := buildTestTable(t, "k", 2, opts)
-	defer t1.DecrRef()
-
-	done := lh0.tryAddLevel0Table(t1)
-	require.Equal(t, true, done)
-	_, span := otrace.StartSpan(context.Background(), "Badger.Compaction")
-	span.Annotatef(nil, "Compaction level: %v", lh0)
-	cd := compactDef{
-		thisLevel: lh0,
-		nextLevel: lh1,
-		span:      span,
-		t:         kv.lc.levelTargets(),
-	}
-	cd.t.baseLevel = 1
-
-	manifest := createManifest()
-	lc, err := newLevelsController(kv, &manifest)
-	require.NoError(t, err)
-	done = lc.fillTablesL0(&cd)
-	require.Equal(t, true, done)
-	lc.runCompactDef(-1, 0, cd)
-	span.End()
-
-	_, span = otrace.StartSpan(context.Background(), "Badger.Compaction")
-	span.Annotatef(nil, "Compaction level: %v", lh0)
-	t2 := buildTestTable(t, "l", 2, opts)
-	defer t2.DecrRef()
-	done = lh0.tryAddLevel0Table(t2)
-	require.Equal(t, true, done)
-
-	cd = compactDef{
-		thisLevel: lh0,
-		nextLevel: lh1,
-		span:      span,
-		t:         kv.lc.levelTargets(),
-	}
-	cd.t.baseLevel = 1
-	lc.fillTablesL0(&cd)
-	lc.runCompactDef(-1, 0, cd)
-}
-
 func TestManifestRewrite(t *testing.T) {
 	dir, err := ioutil.TempDir("", "badger-test")
 	require.NoError(t, err)
diff --git a/memtable.go b/memtable.go
index ccb5fc079..a7c0d0b51 100644
--- a/memtable.go
+++ b/memtable.go
@@ -148,8 +148,6 @@ func (db *DB) openMemTable(fid, flags int) (*memTable, error) {
 	return mt, y.Wrapf(err, "while updating skiplist")
 }
 
-var errExpectingNewFile = errors.New("Expecting to create a new file, but found an existing file")
-
 func (db *DB) newMemTable() (*memTable, error) {
 	mt, err := db.openMemTable(db.nextMemFid, os.O_CREATE|os.O_RDWR)
 	if err == z.NewFile {
diff --git a/merge_test.go b/merge_test.go
index 1bfd8139b..90368bdf3 100644
--- a/merge_test.go
+++ b/merge_test.go
@@ -42,12 +42,9 @@ func TestGetMergeOperator(t *testing.T) {
 			m := db.GetMergeOperator(key, add, 200*time.Millisecond)
 			defer m.Stop()
 
-			err := m.Add(uint64ToBytes(1))
-			require.NoError(t, err)
-			m.Add(uint64ToBytes(2))
-			require.NoError(t, err)
-			m.Add(uint64ToBytes(3))
-			require.NoError(t, err)
+			require.NoError(t, m.Add(uint64ToBytes(1)))
+			require.NoError(t, m.Add(uint64ToBytes(2)))
+			require.NoError(t, m.Add(uint64ToBytes(3)))
 
 			res, err := m.Get()
 			require.NoError(t, err)
@@ -64,12 +61,12 @@ func TestGetMergeOperator(t *testing.T) {
 			m := db.GetMergeOperator([]byte("fooprefix"), add, 2*time.Millisecond)
 			defer m.Stop()
 
-			require.Nil(t, m.Add([]byte("A")))
-			require.Nil(t, m.Add([]byte("B")))
-			require.Nil(t, m.Add([]byte("C")))
+			require.NoError(t, m.Add([]byte("A")))
+			require.NoError(t, m.Add([]byte("B")))
+			require.NoError(t, m.Add([]byte("C")))
 
 			value, err := m.Get()
-			require.Nil(t, err)
+			require.NoError(t, err)
 			require.Equal(t, "ABC", string(value))
 		})
 	})
@@ -79,12 +76,9 @@ func TestGetMergeOperator(t *testing.T) {
 			m := db.GetMergeOperator(key, add, 500*time.Millisecond)
 			defer m.Stop()
 
-			err := m.Add(uint64ToBytes(1))
-			require.NoError(t, err)
-			m.Add(uint64ToBytes(2))
-			require.NoError(t, err)
-			m.Add(uint64ToBytes(3))
-			require.NoError(t, err)
+			require.NoError(t, m.Add(uint64ToBytes(1)))
+			require.NoError(t, m.Add(uint64ToBytes(2)))
+			require.NoError(t, m.Add(uint64ToBytes(3)))
 
 			res, err := m.Get()
 			require.NoError(t, err)
@@ -97,25 +91,21 @@ func TestGetMergeOperator(t *testing.T) {
 		runBadgerTest(t, nil, func(t *testing.T, db *DB) {
 			m := db.GetMergeOperator(key, add, 200*time.Millisecond)
 
-			err := m.Add(uint64ToBytes(1))
-			require.NoError(t, err)
-			m.Add(uint64ToBytes(2))
-			require.NoError(t, err)
-			m.Add(uint64ToBytes(3))
-			require.NoError(t, err)
+			require.NoError(t, m.Add(uint64ToBytes(1)))
+			require.NoError(t, m.Add(uint64ToBytes(2)))
+			require.NoError(t, m.Add(uint64ToBytes(3)))
 
 			m.Stop()
 			res, err := m.Get()
 			require.NoError(t, err)
 			require.Equal(t, uint64(6), bytesToUint64(res))
 
-			db.Update(func(txn *Txn) error {
+			require.NoError(t, db.Update(func(txn *Txn) error {
 				return txn.Delete(key)
-			})
+			}))
 
 			m = db.GetMergeOperator(key, add, 200*time.Millisecond)
-			err = m.Add(uint64ToBytes(1))
-			require.NoError(t, err)
+			require.NoError(t, m.Add(uint64ToBytes(1)))
 			m.Stop()
 
 			res, err = m.Get()
@@ -129,12 +119,9 @@ func TestGetMergeOperator(t *testing.T) {
 		runBadgerTest(t, nil, func(t *testing.T, db *DB) {
 			m := db.GetMergeOperator(key, add, 1*time.Second)
 
-			err := m.Add(uint64ToBytes(1))
-			require.NoError(t, err)
-			m.Add(uint64ToBytes(2))
-			require.NoError(t, err)
-			m.Add(uint64ToBytes(3))
-			require.NoError(t, err)
+			require.NoError(t, m.Add(uint64ToBytes(1)))
+			require.NoError(t, m.Add(uint64ToBytes(2)))
+			require.NoError(t, m.Add(uint64ToBytes(3)))
 
 			m.Stop()
 			res, err := m.Get()
diff --git a/publisher.go b/publisher.go
index 66105fec5..736a13d39 100644
--- a/publisher.go
+++ b/publisher.go
@@ -117,7 +117,7 @@ func (p *publisher) publishUpdates(reqs requests) {
 	}
 }
 
-func (p *publisher) newSubscriber(c *z.Closer, matches []pb.Match) subscriber {
+func (p *publisher) newSubscriber(c *z.Closer, matches []pb.Match) (subscriber, error) {
 	p.Lock()
 	defer p.Unlock()
 	ch := make(chan *pb.KVList, 1000)
@@ -134,9 +134,11 @@ func (p *publisher) newSubscriber(c *z.Closer, matches []pb.Match) subscriber {
 	}
 	p.subscribers[id] = s
 	for _, m := range matches {
-		p.indexer.AddMatch(m, id)
+		if err := p.indexer.AddMatch(m, id); err != nil {
+			return subscriber{}, err
+		}
 	}
-	return s
+	return s, nil
 }
 
 // cleanSubscribers stops all the subscribers. Ideally, It should be called while closing DB.
@@ -145,7 +147,7 @@ func (p *publisher) cleanSubscribers() {
 	defer p.Unlock()
 	for id, s := range p.subscribers {
 		for _, m := range s.matches {
-			p.indexer.DeleteMatch(m, id)
+			_ = p.indexer.DeleteMatch(m, id)
 		}
 		delete(p.subscribers, id)
 		s.subCloser.SignalAndWait()
@@ -157,7 +159,7 @@ func (p *publisher) deleteSubscriber(id uint64) {
 	defer p.Unlock()
 	if s, ok := p.subscribers[id]; ok {
 		for _, m := range s.matches {
-			p.indexer.DeleteMatch(m, id)
+			_ = p.indexer.DeleteMatch(m, id)
 		}
 	}
 	delete(p.subscribers, id)
diff --git a/publisher_test.go b/publisher_test.go
index 73b2f28e3..4f0316424 100644
--- a/publisher_test.go
+++ b/publisher_test.go
@@ -112,10 +112,10 @@ func TestPublisherOrdering(t *testing.T) {
 		}()
 		subWg.Wait()
 		for i := 0; i < 5; i++ {
-			db.Update(func(txn *Txn) error {
+			require.NoError(t, db.Update(func(txn *Txn) error {
 				e := NewEntry([]byte(fmt.Sprintf("key%d", i)), []byte(fmt.Sprintf("value%d", i)))
 				return txn.SetEntry(e)
-			})
+			}))
 		}
 		wg.Wait()
 		for i := 0; i < 5; i++ {
@@ -154,12 +154,12 @@ func TestMultiplePrefix(t *testing.T) {
 			}
 		}()
 		subWg.Wait()
-		db.Update(func(txn *Txn) error {
+		require.NoError(t, db.Update(func(txn *Txn) error {
 			return txn.SetEntry(NewEntry([]byte("key"), []byte("value")))
-		})
-		db.Update(func(txn *Txn) error {
+		}))
+		require.NoError(t, db.Update(func(txn *Txn) error {
 			return txn.SetEntry(NewEntry([]byte("hello"), []byte("badger")))
-		})
+		}))
 		wg.Wait()
 	})
 }
diff --git a/stream.go b/stream.go
index b97b116f0..90ed90d5d 100644
--- a/stream.go
+++ b/stream.go
@@ -181,7 +181,7 @@ func (st *Stream) produceKVs(ctx context.Context, threadId int) error {
 	defer func() {
 		// The outList variable changes. So, we need to evaluate the variable in the defer. DO NOT
 		// call `defer outList.Release()`.
-		outList.Release()
+		_ = outList.Release()
 	}()
 
 	iterate := func(kr keyRange) error {
@@ -295,7 +295,7 @@ func (st *Stream) streamKVs(ctx context.Context) error {
 	now := time.Now()
 
 	sendBatch := func(batch *z.Buffer) error {
-		defer batch.Release()
+		defer func() { _ = batch.Release() }()
 		sz := uint64(batch.LenNoPadding())
 		if sz == 0 {
 			return nil
@@ -432,7 +432,7 @@ func (st *Stream) Orchestrate(ctx context.Context) error {
 	defer func() {
 		// If due to some error, we have buffers left in kvChan, we should release them.
 		for buf := range st.kvChan {
-			buf.Release()
+			_ = buf.Release()
 		}
 	}()
 
diff --git a/stream_writer_test.go b/stream_writer_test.go
index c4922be15..2180804a7 100644
--- a/stream_writer_test.go
+++ b/stream_writer_test.go
@@ -176,7 +176,7 @@ func TestStreamWriter3(t *testing.T) {
 			y.Check2(rand.Read(value))
 			counter := 0
 			buf := z.NewBuffer(10<<20, "test")
-			defer buf.Release()
+			defer func() { require.NoError(t, buf.Release()) }()
 			for i := 0; i < noOfKeys; i++ {
 				key := make([]byte, 8)
 				binary.BigEndian.PutUint64(key, uint64(counter))
@@ -273,7 +273,7 @@ func TestStreamWriter4(t *testing.T) {
 		}
 
 		buf := z.NewBuffer(10<<20, "test")
-		defer buf.Release()
+		defer func() { require.NoError(t, buf.Release()) }()
 		KVToBuffer(&pb.KV{
 			Key:     []byte("key-1"),
 			Value:   []byte("value-1"),
@@ -298,7 +298,7 @@ func TestStreamWriter5(t *testing.T) {
 		copy(right[1:], []byte("break"))
 
 		buf := z.NewBuffer(10<<20, "test")
-		defer buf.Release()
+		defer func() { require.NoError(t, buf.Release()) }()
 		KVToBuffer(&pb.KV{
 			Key:     left,
 			Value:   []byte("val"),
@@ -337,7 +337,7 @@ func TestStreamWriter6(t *testing.T) {
 		// Setting keycount below 32 would cause this test to fail.
 		keyCount := 40
 		buf := z.NewBuffer(10<<20, "test")
-		defer buf.Release()
+		defer func() { require.NoError(t, buf.Release()) }()
 		for i := range str {
 			for j := 0; j < keyCount; j++ {
 				ver++
@@ -378,7 +378,7 @@ func TestStreamWriterCancel(t *testing.T) {
 		str := []string{"a", "a", "b", "b", "c", "c"}
 		ver := 1
 		buf := z.NewBuffer(10<<20, "test")
-		defer buf.Release()
+		defer func() { require.NoError(t, buf.Release()) }()
 		for i := range str {
 			kv := &pb.KV{
 				Key:     bytes.Repeat([]byte(str[i]), int(db.opt.BaseTableSize)),
@@ -412,7 +412,7 @@ func TestStreamDone(t *testing.T) {
 		rand.Read(val[:])
 		for i := 0; i < 10; i++ {
 			buf := z.NewBuffer(10<<20, "test")
-			defer buf.Release()
+			defer func() { require.NoError(t, buf.Release()) }()
 			kv1 := &pb.KV{
 				Key:      []byte(fmt.Sprintf("%d", i)),
 				Value:    val[:],
@@ -453,7 +453,7 @@ func TestSendOnClosedStream(t *testing.T) {
 	var val [10]byte
 	rand.Read(val[:])
 	buf := z.NewBuffer(10<<20, "test")
-	defer buf.Release()
+	defer func() { require.NoError(t, buf.Release()) }()
 	kv1 := &pb.KV{
 		Key:      []byte(fmt.Sprintf("%d", 1)),
 		Value:    val[:],
@@ -476,7 +476,7 @@ func TestSendOnClosedStream(t *testing.T) {
 	}()
 	// Send once stream is closed.
 	buf1 := z.NewBuffer(10<<20, "test")
-	defer buf1.Release()
+	defer func() { require.NoError(t, buf1.Release()) }()
 	kv1 = &pb.KV{
 		Key:      []byte(fmt.Sprintf("%d", 2)),
 		Value:    val[:],
@@ -484,7 +484,7 @@ func TestSendOnClosedStream(t *testing.T) {
 		StreamId: uint32(1),
 	}
 	KVToBuffer(kv1, buf1)
-	sw.Write(buf1)
+	require.NoError(t, sw.Write(buf1))
 }
 
 func TestSendOnClosedStream2(t *testing.T) {
@@ -503,7 +503,7 @@ func TestSendOnClosedStream2(t *testing.T) {
 	var val [10]byte
 	rand.Read(val[:])
 	buf := z.NewBuffer(10<<20, "test")
-	defer buf.Release()
+	defer func() { require.NoError(t, buf.Release()) }()
 	kv1 := &pb.KV{
 		Key:      []byte(fmt.Sprintf("%d", 1)),
 		Value:    val[:],
@@ -550,7 +550,7 @@ func TestStreamWriterEncrypted(t *testing.T) {
 	value := []byte("myvalue")
 
 	buf := z.NewBuffer(10<<20, "test")
-	defer buf.Release()
+	defer func() { require.NoError(t, buf.Release()) }()
 	KVToBuffer(&pb.KV{
 		Key:     key,
 		Value:   value,
diff --git a/structs.go b/structs.go
index c17f818cf..f51c4a655 100644
--- a/structs.go
+++ b/structs.go
@@ -174,6 +174,7 @@ func (e *Entry) skipVlogAndSetThreshold(threshold int64) bool {
 	return int64(len(e.Value)) < e.valThreshold
 }
 
+//nolint:unused
 func (e Entry) print(prefix string) {
 	fmt.Printf("%s Key: %s Meta: %d UserMeta: %d Offset: %d len(val)=%d",
 		prefix, e.Key, e.meta, e.UserMeta, e.offset, len(e.Value))
diff --git a/table/builder.go b/table/builder.go
index da5a23a0f..3debe08e2 100644
--- a/table/builder.go
+++ b/table/builder.go
@@ -84,7 +84,6 @@ type Builder struct {
 	uncompressedSize uint32
 
 	lenOffsets    uint32
-	estimatedSize uint32
 	keyHashes     []uint32 // Used for building the bloomfilter.
 	opts          *Options
 	maxVersion    uint64
@@ -291,7 +290,6 @@ func (b *Builder) finishBlock() {
 	if b.blockChan != nil {
 		b.blockChan <- b.curBlock
 	}
-	return
 }
 
 func (b *Builder) shouldFinishBlock(key []byte, value y.ValueStruct) bool {
diff --git a/table/merge_iterator.go b/table/merge_iterator.go
index 789a24fd7..70ccc0858 100644
--- a/table/merge_iterator.go
+++ b/table/merge_iterator.go
@@ -115,7 +115,7 @@ func (mi *MergeIterator) fix() {
 	case cmp < 0: // Small is less than bigger().
 		if mi.reverse {
 			mi.swapSmall()
-		} else {
+		} else { //nolint:staticcheck
 			// we don't need to do anything. Small already points to the smallest.
 		}
 		return
diff --git a/table/table.go b/table/table.go
index 1838fe7e6..6c5704feb 100644
--- a/table/table.go
+++ b/table/table.go
@@ -379,7 +379,7 @@ func (t *Table) initBiggestAndSmallest() error {
 			checksum := &pb.Checksum{}
 			readPos -= checksumLen
 			buf = t.readNoFail(readPos, checksumLen)
-			proto.Unmarshal(buf, checksum)
+			_ = proto.Unmarshal(buf, checksum)
 			fmt.Fprintf(&debugBuf, "checksum: %+v ", checksum)
 
 			// Read index size from the footer.
@@ -828,7 +828,7 @@ func (t *Table) decompress(b *block) error {
 		return errors.New("Unsupported compression type")
 	}
 
-	if b.freeMe == true {
+	if b.freeMe {
 		z.Free(src)
 		b.freeMe = false
 	}
diff --git a/table/table_test.go b/table/table_test.go
index e2f0fcb92..183d8b62a 100644
--- a/table/table_test.go
+++ b/table/table_test.go
@@ -90,7 +90,7 @@ func TestTableIterator(t *testing.T) {
 		t.Run(fmt.Sprintf("n=%d", n), func(t *testing.T) {
 			opts := getTestTableOptions()
 			table := buildTestTable(t, "key", n, opts)
-			defer table.DecrRef()
+			defer func() { require.NoError(t, table.DecrRef()) }()
 			it := table.NewIterator(0)
 			defer it.Close()
 			count := 0
@@ -111,7 +111,7 @@ func TestSeekToFirst(t *testing.T) {
 		t.Run(fmt.Sprintf("n=%d", n), func(t *testing.T) {
 			opts := getTestTableOptions()
 			table := buildTestTable(t, "key", n, opts)
-			defer table.DecrRef()
+			defer func() { require.NoError(t, table.DecrRef()) }()
 			it := table.NewIterator(0)
 			defer it.Close()
 			it.seekToFirst()
@@ -128,7 +128,7 @@ func TestSeekToLast(t *testing.T) {
 		t.Run(fmt.Sprintf("n=%d", n), func(t *testing.T) {
 			opts := getTestTableOptions()
 			table := buildTestTable(t, "key", n, opts)
-			defer table.DecrRef()
+			defer func() { require.NoError(t, table.DecrRef()) }()
 			it := table.NewIterator(0)
 			defer it.Close()
 			it.seekToLast()
@@ -148,7 +148,7 @@ func TestSeekToLast(t *testing.T) {
 func TestSeek(t *testing.T) {
 	opts := getTestTableOptions()
 	table := buildTestTable(t, "k", 10000, opts)
-	defer table.DecrRef()
+	defer func() { require.NoError(t, table.DecrRef()) }()
 
 	it := table.NewIterator(0)
 	defer it.Close()
@@ -182,7 +182,7 @@ func TestSeek(t *testing.T) {
 func TestSeekForPrev(t *testing.T) {
 	opts := getTestTableOptions()
 	table := buildTestTable(t, "k", 10000, opts)
-	defer table.DecrRef()
+	defer func() { require.NoError(t, table.DecrRef()) }()
 
 	it := table.NewIterator(0)
 	defer it.Close()
@@ -219,7 +219,7 @@ func TestIterateFromStart(t *testing.T) {
 		t.Run(fmt.Sprintf("n=%d", n), func(t *testing.T) {
 			opts := getTestTableOptions()
 			table := buildTestTable(t, "key", n, opts)
-			defer table.DecrRef()
+			defer func() { require.NoError(t, table.DecrRef()) }()
 			ti := table.NewIterator(0)
 			defer ti.Close()
 			ti.reset()
@@ -245,7 +245,7 @@ func TestIterateFromEnd(t *testing.T) {
 		t.Run(fmt.Sprintf("n=%d", n), func(t *testing.T) {
 			opts := getTestTableOptions()
 			table := buildTestTable(t, "key", n, opts)
-			defer table.DecrRef()
+			defer func() { require.NoError(t, table.DecrRef()) }()
 			ti := table.NewIterator(0)
 			defer ti.Close()
 			ti.reset()
@@ -267,7 +267,7 @@ func TestIterateFromEnd(t *testing.T) {
 func TestTable(t *testing.T) {
 	opts := getTestTableOptions()
 	table := buildTestTable(t, "key", 10000, opts)
-	defer table.DecrRef()
+	defer func() { require.NoError(t, table.DecrRef()) }()
 	ti := table.NewIterator(0)
 	defer ti.Close()
 	kid := 1010
@@ -293,7 +293,7 @@ func TestTable(t *testing.T) {
 func TestIterateBackAndForth(t *testing.T) {
 	opts := getTestTableOptions()
 	table := buildTestTable(t, "key", 10000, opts)
-	defer table.DecrRef()
+	defer func() { require.NoError(t, table.DecrRef()) }()
 
 	seek := y.KeyWithTs([]byte(key("key", 1010)), 0)
 	it := table.NewIterator(0)
@@ -333,7 +333,7 @@ func TestIterateBackAndForth(t *testing.T) {
 func TestUniIterator(t *testing.T) {
 	opts := getTestTableOptions()
 	table := buildTestTable(t, "key", 10000, opts)
-	defer table.DecrRef()
+	defer func() { require.NoError(t, table.DecrRef()) }()
 	{
 		it := table.NewIterator(0)
 		defer it.Close()
@@ -368,7 +368,7 @@ func TestConcatIteratorOneTable(t *testing.T) {
 		{"k2", "a2"},
 	}, opts)
 
-	defer tbl.DecrRef()
+	defer func() { require.NoError(t, tbl.DecrRef()) }()
 
 	it := NewConcatIterator([]*Table{tbl}, 0)
 	defer it.Close()
@@ -387,9 +387,9 @@ func TestConcatIterator(t *testing.T) {
 	tbl := buildTestTable(t, "keya", 10000, opts)
 	tbl2 := buildTestTable(t, "keyb", 10000, opts)
 	tbl3 := buildTestTable(t, "keyc", 10000, opts)
-	defer tbl.DecrRef()
-	defer tbl2.DecrRef()
-	defer tbl3.DecrRef()
+	defer func() { require.NoError(t, tbl.DecrRef()) }()
+	defer func() { require.NoError(t, tbl2.DecrRef()) }()
+	defer func() { require.NoError(t, tbl2.DecrRef()) }()
 
 	{
 		it := NewConcatIterator([]*Table{tbl, tbl2, tbl3}, 0)
@@ -480,8 +480,8 @@ func TestMergingIterator(t *testing.T) {
 		{"k4", "a4"},
 		{"k5", "a5"},
 	}
-	defer tbl1.DecrRef()
-	defer tbl2.DecrRef()
+	defer func() { require.NoError(t, tbl1.DecrRef()) }()
+	defer func() { require.NoError(t, tbl2.DecrRef()) }()
 	it1 := tbl1.NewIterator(0)
 	it2 := NewConcatIterator([]*Table{tbl2}, 0)
 	it := NewMergeIterator([]y.Iterator{it1, it2}, false)
@@ -525,8 +525,8 @@ func TestMergingIteratorReversed(t *testing.T) {
 		{"k2", "a2"},
 		{"k1", "a1"},
 	}
-	defer tbl1.DecrRef()
-	defer tbl2.DecrRef()
+	defer func() { require.NoError(t, tbl1.DecrRef()) }()
+	defer func() { require.NoError(t, tbl2.DecrRef()) }()
 	it1 := tbl1.NewIterator(REVERSED)
 	it2 := NewConcatIterator([]*Table{tbl2}, REVERSED)
 	it := NewMergeIterator([]y.Iterator{it1, it2}, true)
@@ -555,8 +555,8 @@ func TestMergingIteratorTakeOne(t *testing.T) {
 	}, opts)
 	t2 := buildTable(t, [][]string{{"l1", "b1"}}, opts)
 
-	defer t1.DecrRef()
-	defer t2.DecrRef()
+	defer func() { require.NoError(t, t1.DecrRef()) }()
+	defer func() { require.NoError(t, t2.DecrRef()) }()
 
 	it1 := NewConcatIterator([]*Table{t1}, 0)
 	it2 := NewConcatIterator([]*Table{t2}, 0)
@@ -599,8 +599,8 @@ func TestMergingIteratorTakeTwo(t *testing.T) {
 		{"k2", "a2"},
 	}, opts)
 
-	defer t1.DecrRef()
-	defer t2.DecrRef()
+	defer func() { require.NoError(t, t1.DecrRef()) }()
+	defer func() { require.NoError(t, t2.DecrRef()) }()
 
 	it1 := NewConcatIterator([]*Table{t1}, 0)
 	it2 := NewConcatIterator([]*Table{t2}, 0)
@@ -656,7 +656,7 @@ func TestTableBigValues(t *testing.T) {
 	filename := fmt.Sprintf("%s%s%d.sst", os.TempDir(), string(os.PathSeparator), rand.Int63())
 	tbl, err := CreateTable(filename, builder)
 	require.NoError(t, err, "unable to open table")
-	defer tbl.DecrRef()
+	defer func() { require.NoError(t, tbl.DecrRef()) }()
 
 	itr := tbl.NewIterator(0)
 	require.True(t, itr.Valid())
@@ -705,7 +705,7 @@ var cacheConfig = ristretto.Config{
 func BenchmarkRead(b *testing.B) {
 	n := int(5 * 1e6)
 	tbl := getTableForBenchmarks(b, n, nil)
-	defer tbl.DecrRef()
+	defer func() { _ = tbl.DecrRef() }()
 
 	b.ResetTimer()
 	// Iterate b.N times over the entire table.
@@ -724,7 +724,7 @@ func BenchmarkReadAndBuild(b *testing.B) {
 
 	var cache, _ = ristretto.NewCache(&cacheConfig)
 	tbl := getTableForBenchmarks(b, n, cache)
-	defer tbl.DecrRef()
+	defer func() { _ = tbl.DecrRef() }()
 
 	b.ResetTimer()
 	// Iterate b.N times over the entire table.
@@ -770,7 +770,7 @@ func BenchmarkReadMerged(b *testing.B) {
 		y.Check(err)
 		builder.Close()
 		tables = append(tables, tbl)
-		defer tbl.DecrRef()
+		defer func() { _ = tbl.DecrRef() }()
 	}
 
 	b.ResetTimer()
@@ -814,7 +814,7 @@ func BenchmarkChecksum(b *testing.B) {
 func BenchmarkRandomRead(b *testing.B) {
 	n := int(5 * 1e6)
 	tbl := getTableForBenchmarks(b, n, nil)
-	defer tbl.DecrRef()
+	defer func() { _ = tbl.DecrRef() }()
 
 	r := rand.New(rand.NewSource(time.Now().Unix()))
 
@@ -870,7 +870,7 @@ func TestMain(m *testing.M) {
 func TestDoesNotHaveRace(t *testing.T) {
 	opts := getTestTableOptions()
 	table := buildTestTable(t, "key", 10000, opts)
-	defer table.DecrRef()
+	defer func() { require.NoError(t, table.DecrRef()) }()
 
 	var wg sync.WaitGroup
 	wg.Add(5)
diff --git a/trie/trie.go b/trie/trie.go
index 331207b5c..ec2434d4b 100644
--- a/trie/trie.go
+++ b/trie/trie.go
@@ -69,7 +69,7 @@ func parseIgnoreBytes(ig string) ([]bool, error) {
 		if len(r) == 0 || len(r) > 2 {
 			return out, fmt.Errorf("Invalid range: %s", each)
 		}
-		start, end := -1, -1
+		start, end := -1, -1 //nolint:ineffassign
 		if len(r) == 2 {
 			idx, err := strconv.Atoi(strings.TrimSpace(r[1]))
 			if err != nil {
diff --git a/trie/trie_test.go b/trie/trie_test.go
index 40a1e4574..1f55ecb6d 100644
--- a/trie/trie_test.go
+++ b/trie/trie_test.go
@@ -65,20 +65,20 @@ func TestTrieDelete(t *testing.T) {
 
 	t.Logf("Num nodes: %d", numNodes(trie.root))
 
-	trie.Delete([]byte("hello"), 4)
+	require.NoError(t, trie.Delete([]byte("hello"), 4))
 	t.Logf("Num nodes: %d", numNodes(trie.root))
 
 	require.Equal(t, map[uint64]struct{}{5: {}, 1: {}, 3: {}}, trie.Get([]byte("hello")))
 
-	trie.Delete(nil, 5)
+	require.NoError(t, trie.Delete(nil, 5))
 	t.Logf("Num nodes: %d", numNodes(trie.root))
 	require.Equal(t, map[uint64]struct{}{1: {}, 3: {}}, trie.Get([]byte("hello")))
 
-	trie.Delete([]byte("hello"), 1)
-	trie.Delete([]byte("hello"), 3)
-	trie.Delete([]byte("hello"), 4)
-	trie.Delete([]byte("hello"), 5)
-	trie.Delete([]byte("hello"), 6)
+	require.NoError(t, trie.Delete([]byte("hello"), 1))
+	require.NoError(t, trie.Delete([]byte("hello"), 3))
+	require.NoError(t, trie.Delete([]byte("hello"), 4))
+	require.NoError(t, trie.Delete([]byte("hello"), 5))
+	require.NoError(t, trie.Delete([]byte("hello"), 6))
 
 	require.Equal(t, 1, numNodes(trie.root))
 	t.Logf("Num nodes: %d", numNodes(trie.root))
diff --git a/txn_test.go b/txn_test.go
index 61d592e2d..12b950391 100644
--- a/txn_test.go
+++ b/txn_test.go
@@ -50,7 +50,7 @@ func TestTxnSimple(t *testing.T) {
 			return nil
 		}))
 
-		require.Panics(t, func() { txn.CommitAt(100, nil) })
+		require.Panics(t, func() { _ = txn.CommitAt(100, nil) })
 		require.NoError(t, txn.Commit())
 	})
 }
@@ -368,7 +368,7 @@ func TestTxnIterationEdgeCase(t *testing.T) {
 
 		// b4 (del)
 		txn = db.NewTransaction(true)
-		txn.Delete(kb)
+		require.NoError(t, txn.Delete(kb))
 		require.NoError(t, txn.Commit())
 		require.Equal(t, uint64(4), db.orc.readTs())
 
@@ -452,7 +452,7 @@ func TestTxnIterationEdgeCase2(t *testing.T) {
 
 		// b4 (del)
 		txn = db.NewTransaction(true)
-		txn.Delete(kb)
+		require.NoError(t, txn.Delete(kb))
 		require.NoError(t, txn.Commit())
 		require.Equal(t, uint64(4), db.orc.readTs())
 
@@ -750,7 +750,7 @@ func TestManagedDB(t *testing.T) {
 		}
 
 		require.Panics(t, func() {
-			db.Update(func(tx *Txn) error { return nil })
+			_ = db.Update(func(tx *Txn) error { return nil })
 		})
 
 		err = db.View(func(tx *Txn) error { return nil })
@@ -821,7 +821,8 @@ func TestManagedDB(t *testing.T) {
 		// Write data to same key, causing a conflict
 		txn = db.NewTransactionAt(10, true)
 		txnb := db.NewTransactionAt(10, true)
-		txnb.Get(key(0))
+		_, err := txnb.Get(key(0))
+		require.NoError(t, err)
 		require.NoError(t, txn.SetEntry(NewEntry(key(0), val(0))))
 		require.NoError(t, txnb.SetEntry(NewEntry(key(0), val(1))))
 		require.NoError(t, txn.CommitAt(11, nil))
diff --git a/value.go b/value.go
index fb2fdca72..87fa1d64c 100644
--- a/value.go
+++ b/value.go
@@ -55,7 +55,7 @@ const (
 	bitTxn    byte = 1 << 6 // Set if the entry is part of a txn.
 	bitFinTxn byte = 1 << 7 // Set if the entry is to indicate end of txn in value log.
 
-	mi int64 = 1 << 20
+	mi int64 = 1 << 20 //nolint:unused
 
 	// size of vlog header.
 	// +----------------+------------------+
@@ -66,7 +66,6 @@ const (
 
 var errStop = errors.New("Stop iteration")
 var errTruncate = errors.New("Do truncate")
-var errDeleteVlogFile = errors.New("Delete vlog file")
 
 type logEntry func(e Entry, vp valuePointer) error
 
@@ -251,7 +250,7 @@ func (vlog *valueLog) rewrite(f *logFile) error {
 			}
 			wb = append(wb, ne)
 			size += es
-		} else {
+		} else { //nolint:staticcheck
 			// It might be possible that the entry read from LSM Tree points to
 			// an older vlog file.  This can happen in the following situation.
 			// Assume DB is opened with
@@ -820,7 +819,9 @@ func (vlog *valueLog) write(reqs []*request) error {
 		endOffset := atomic.AddUint32(&vlog.writableLogOffset, n)
 		// Increase the file size if we cannot accommodate this entry.
 		if int(endOffset) >= len(curlf.Data) {
-			curlf.Truncate(int64(endOffset))
+			if err := curlf.Truncate(int64(endOffset)); err != nil {
+				return err
+			}
 		}
 
 		start := int(endOffset - n)
@@ -1056,12 +1057,6 @@ func discardEntry(e Entry, vs y.ValueStruct, db *DB) bool {
 	return false
 }
 
-type reason struct {
-	total   float64
-	discard float64
-	count   int
-}
-
 func (vlog *valueLog) doRunGC(lf *logFile) error {
 	_, span := otrace.StartSpan(context.Background(), "Badger.GC")
 	span.Annotatef(nil, "GC rewrite for: %v", lf.path)
diff --git a/value_test.go b/value_test.go
index 69f02e171..e138a6c79 100644
--- a/value_test.go
+++ b/value_test.go
@@ -18,6 +18,7 @@ package badger
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"math"
@@ -53,7 +54,7 @@ func TestDynamicValueThreshold(t *testing.T) {
 			}
 			b := new(request)
 			b.Entries = []*Entry{e1}
-			log.write([]*request{b})
+			require.NoError(t, log.write([]*request{b}))
 		}
 		t.Logf("value threshold is %d \n", log.db.valueThreshold())
 	}
@@ -69,7 +70,7 @@ func TestDynamicValueThreshold(t *testing.T) {
 			}
 			b := new(request)
 			b.Entries = []*Entry{e1}
-			log.write([]*request{b})
+			require.NoError(t, log.write([]*request{b}))
 		}
 		t.Logf("value threshold is %d \n", log.db.valueThreshold())
 	}
@@ -104,7 +105,7 @@ func TestValueBasic(t *testing.T) {
 	b := new(request)
 	b.Entries = []*Entry{e1, e2}
 
-	log.write([]*request{b})
+	require.NoError(t, log.write([]*request{b}))
 	require.Len(t, b.Ptrs, 2)
 	t.Logf("Pointer written: %+v %+v\n", b.Ptrs[0], b.Ptrs[1])
 
@@ -192,7 +193,7 @@ func TestValueGCManaged(t *testing.T) {
 	}
 
 	db.SetDiscardTs(math.MaxUint32)
-	db.Flatten(3)
+	require.NoError(t, db.Flatten(3))
 
 	for i := 0; i < 100; i++ {
 		// Try at max 100 times to GC even a single value log file.
@@ -241,7 +242,7 @@ func TestValueGC(t *testing.T) {
 	//		return true
 	//	})
 
-	kv.vlog.rewrite(lf)
+	require.NoError(t, kv.vlog.rewrite(lf))
 	for i := 45; i < 100; i++ {
 		key := []byte(fmt.Sprintf("key%d", i))
 
@@ -299,7 +300,7 @@ func TestValueGC2(t *testing.T) {
 	//		return true
 	//	})
 
-	kv.vlog.rewrite(lf)
+	require.NoError(t, kv.vlog.rewrite(lf))
 	for i := 0; i < 5; i++ {
 		key := []byte(fmt.Sprintf("key%d", i))
 		require.NoError(t, kv.View(func(txn *Txn) error {
@@ -397,7 +398,7 @@ func TestValueGC3(t *testing.T) {
 	logFile := kv.vlog.filesMap[kv.vlog.sortedFids()[0]]
 	kv.vlog.filesLock.RUnlock()
 
-	kv.vlog.rewrite(logFile)
+	require.NoError(t, kv.vlog.rewrite(logFile))
 	it.Next()
 	require.True(t, it.Valid())
 	item = it.Item()
@@ -452,8 +453,8 @@ func TestValueGC4(t *testing.T) {
 	//		return true
 	//	})
 
-	kv.vlog.rewrite(lf0)
-	kv.vlog.rewrite(lf1)
+	require.NoError(t, kv.vlog.rewrite(lf0))
+	require.NoError(t, kv.vlog.rewrite(lf1))
 
 	require.NoError(t, kv.Close())
 
@@ -812,6 +813,7 @@ func TestPenultimateMemCorruption(t *testing.T) {
 	require.Zero(t, len(db0.imm))
 	db0.imm = append(db0.imm, db0.mt)
 	db0.mt, err = db0.newMemTable()
+	require.NoError(t, err)
 
 	h.writeRange(3, 7) // 00002.mem
 
@@ -826,7 +828,7 @@ func TestPenultimateMemCorruption(t *testing.T) {
 		if i == 1 {
 			// This should corrupt the last entry in the first memtable (that is entry number 2)
 			wal := db0.imm[0].wal
-			wal.Fd.WriteAt([]byte{0}, int64(wal.writeAt-1))
+			_, err = wal.Fd.WriteAt([]byte{0}, int64(wal.writeAt-1))
 			require.NoError(t, err)
 			// We have corrupted the file. We can remove it. If we don't remove
 			// the imm here, the db.close in defer will crash since db0.mt !=
@@ -943,7 +945,9 @@ func TestBug578(t *testing.T) {
 
 		// Run value log GC a few times.
 		for i := 0; i < 5; i++ {
-			db.RunValueLogGC(0.5)
+			if err := db.RunValueLogGC(0.5); err != nil && !errors.Is(ErrNoRewrite, err) {
+				require.NoError(t, err)
+			}
 		}
 		h.readRange(0, 10)
 	}
@@ -980,12 +984,12 @@ func BenchmarkReadWrite(b *testing.B) {
 
 					var ptrs []valuePointer
 
-					vl.write([]*request{bl})
+					_ = vl.write([]*request{bl})
 					ptrs = append(ptrs, bl.Ptrs...)
 
 					f := rand.Float32()
 					if f < rw {
-						vl.write([]*request{bl})
+						_ = vl.write([]*request{bl})
 
 					} else {
 						ln := len(ptrs)
@@ -1233,10 +1237,11 @@ func TestValueLogMeta(t *testing.T) {
 	require.Equal(t, 1, len(fids))
 
 	// vlog entries must not have txn meta.
-	db.vlog.filesMap[fids[0]].iterate(true, 0, func(e Entry, vp valuePointer) error {
+	_, err = db.vlog.filesMap[fids[0]].iterate(true, 0, func(e Entry, vp valuePointer) error {
 		require.Zero(t, e.meta&(bitTxn|bitFinTxn))
 		return nil
 	})
+	require.NoError(t, err)
 
 	// Entries in LSM tree must have txn bit of meta set
 	txn = db.NewTransaction(false)
@@ -1264,6 +1269,7 @@ func TestFirstVlogFile(t *testing.T) {
 
 	opt := DefaultOptions(dir)
 	db, err := Open(opt)
+	require.NoError(t, err)
 	defer db.Close()
 
 	fids := db.vlog.sortedFids()
diff --git a/y/encrypt_test.go b/y/encrypt_test.go
index 91d50acb1..ded05828a 100644
--- a/y/encrypt_test.go
+++ b/y/encrypt_test.go
@@ -26,19 +26,19 @@ import (
 
 func TestXORBlock(t *testing.T) {
 	key := make([]byte, 32)
-	rand.Read(key)
+	_, _ = rand.Read(key)
 
 	var iv []byte
 	{
 		b, err := aes.NewCipher(key)
 		require.NoError(t, err)
 		iv = make([]byte, b.BlockSize())
-		rand.Read(iv)
+		_, _ = rand.Read(iv)
 		t.Logf("Using %d size IV\n", len(iv))
 	}
 
 	src := make([]byte, 1024)
-	rand.Read(src)
+	_, _ = rand.Read(src)
 
 	dst := make([]byte, 1024)
 	err := XORBlock(dst, src, key, iv)
diff --git a/y/y_test.go b/y/y_test.go
index fc19d27e2..ce4cab2b2 100644
--- a/y/y_test.go
+++ b/y/y_test.go
@@ -34,7 +34,7 @@ func BenchmarkBuffer(b *testing.B) {
 		b.Run(fmt.Sprintf("page-size-%d", pageSize), func(b *testing.B) {
 			pageBuffer := NewPageBuffer(pageSize)
 			for i := 0; i < b.N; i++ {
-				pageBuffer.Write(btw[:])
+				_, _ = pageBuffer.Write(btw[:])
 			}
 		})
 	})