[#17130] YSQL: Refactor ADD/DROP PK to use new table rewrite approach

Summary:
This diff changes `ADD/DROP PK` to use the new table rewrite approach. The old code is kept to avoid issues with upgrade (as the new table rewrite code-paths are guarded with the auto-flag `yb_enable_alter_table_rewrite`); however, it will be removed in a future release.

Specific code changes:
  - Add another reason for rewrite: `YB_AT_REWRITE_ALTER_PRIMARY_KEY`. Table rewrite is required in YB when changing the primary key.
  - In `ALTER TABLE` phase 2, when executing add/drop primary key for partitioned tables, add the children to the `ALTER TABLE` work queue and mark them to be re-written (see `ATExecAddIndex` and `ATExecDropConstraint`). Rewrites for all tables in the work queue are handled in phase 3 (`ATRewriteTables`)
  - Add `yb_skip_copy_split_options` to `AlterTableInfo`. Split properties are not preserved when adding a range primary key (see D23931 for more details).
  - Increment schema version for the old DocDB table during table rewrite, so that concurrent DMLs get aborted with a `schema version mismatch`. Additionally, add tests for table rewrite operations in `TestAlterTableWithConcurrentTxn.java`.
  - Move rewrite tests in `yb_alter_table` into `yb_alter_table_rewrite` (in `yb_table_serial_schedule`).
  - Delete `TestPgAlterTableChangePrimaryKey`, and move the relevant tests into `yb_alter_table_rewrite`.
Jira: DB-6412

Test Plan: `yb_alter_table_rewrite` in `yb_table_serial_schedule`

Reviewers: dsrinivasan, myang

Reviewed By: myang

Subscribers: ybase, jason, yql

Differential Revision: https://phorge.dev.yugabyte.com/D29786

java/yb-pgsql/src/test/java/org/yb/pgsql/TestAlterTableWithConcurrentTxn.java

@@ -52,7 +52,9 @@ private static enum AlterCommand {
       DROP_IDENTITY, ADD_IDENTITY,
       ENABLE_ROW_SECURITY, DISABLE_ROW_SECURITY,
       ATTACH_PARTITION, DETACH_PARTITION,
-      ADD_FOREIGN_KEY, DROP_FOREIGN_KEY }
+      ADD_FOREIGN_KEY, DROP_FOREIGN_KEY,
+      ADD_PRIMARY_KEY, DROP_PRIMARY_KEY,
+      ADD_COLUMN_WITH_VOLATILE_DEFAULT}
 
   private void prepareAndPopulateTable(AlterCommand alterCommand, String tableName)
       throws Exception {
@@ -77,7 +79,12 @@ private void prepareAndPopulateTable(AlterCommand alterCommand, String tableName
       }
 
       // Create table
-      String createTableQuery = "CREATE TABLE " + tableName + " (a INT PRIMARY KEY";
+      String createTableQuery = "CREATE TABLE " + tableName;
+      if (alterCommand == AlterCommand.ADD_PRIMARY_KEY) {
+        createTableQuery += " (a INT";
+      } else {
+        createTableQuery += " (a INT PRIMARY KEY";
+      }
       if (alterCommand == AlterCommand.DROP_CONSTRAINT) {
         createTableQuery += " CONSTRAINT positive CHECK (a > 0)";
       }
@@ -146,7 +153,10 @@ private void prepareAndPopulateTable(AlterCommand alterCommand, String tableName
         case DISABLE_ROW_SECURITY:
         case DROP_IDENTITY:
         case ATTACH_PARTITION:
-        case DETACH_PARTITION: {
+        case DETACH_PARTITION:
+        case ADD_PRIMARY_KEY:
+        case DROP_PRIMARY_KEY:
+        case ADD_COLUMN_WITH_VOLATILE_DEFAULT: {
           statement.execute("INSERT INTO " + tableName + " VALUES (1, 'foo')");
           break;
         }
@@ -178,6 +188,8 @@ private void prepareAndPopulateTable(AlterCommand alterCommand, String tableName
   }
 
   private String getAlterSql(AlterCommand alterCommand, String tableName) throws Exception {
+    // Set test flag to skip dropping old tables for table rewrite operations.
+    String rewriteTestFlag = "SET yb_test_table_rewrite_keep_old_table=true;";
     switch (alterCommand) {
       case DROP_COLUMN: {
         return "ALTER TABLE " + tableName + " DROP COLUMN b";
@@ -238,6 +250,17 @@ private String getAlterSql(AlterCommand alterCommand, String tableName) throws E
       case DROP_FOREIGN_KEY: {
         return "ALTER TABLE " + tableName + "_f DROP CONSTRAINT c";
       }
+      case ADD_PRIMARY_KEY: {
+        return rewriteTestFlag + "ALTER TABLE " + tableName + " ADD PRIMARY KEY (a)";
+      }
+      case DROP_PRIMARY_KEY: {
+        return rewriteTestFlag + "ALTER TABLE " + tableName + " DROP CONSTRAINT " + tableName
+          + "_pkey";
+      }
+      case ADD_COLUMN_WITH_VOLATILE_DEFAULT: {
+        return rewriteTestFlag + "ALTER TABLE " + tableName
+          + " ADD COLUMN d float DEFAULT random()";
+      }
       default: {
         throw new Exception("Alter command type " + alterCommand + " not supported");
       }
@@ -275,7 +298,9 @@ private String getDmlSql(Dml dmlToExecute, AlterCommand alterCommand,
           case SET_NOT_NULL:
           case DROP_NOT_NULL:
           case ENABLE_ROW_SECURITY:
-          case DISABLE_ROW_SECURITY: {
+          case DISABLE_ROW_SECURITY:
+          case ADD_PRIMARY_KEY:
+          case DROP_PRIMARY_KEY: {
             return "INSERT INTO " + tableName + " VALUES (2, 'foo')";
           }
           case ADD_FOREIGN_KEY:
@@ -313,6 +338,13 @@ private String getDmlSql(Dml dmlToExecute, AlterCommand alterCommand,
               return "INSERT INTO " + tableName + " VALUES (2, 'bar', 2)";
             }
           }
+          case ADD_COLUMN_WITH_VOLATILE_DEFAULT: {
+            if (useOriginalSchema) {
+              return "INSERT INTO " + tableName + " VALUES (2, 'bar')";
+            } else {
+              return "INSERT INTO " + tableName + " VALUES (2, 'bar', 2.0)";
+            }
+          }
           default: {
             throw new Exception("Alter command type " + alterCommand + " not supported");
           }
@@ -337,6 +369,9 @@ private String getDmlSql(Dml dmlToExecute, AlterCommand alterCommand,
           case DROP_IDENTITY:
           case ADD_FOREIGN_KEY:
           case DROP_FOREIGN_KEY:
+          case ADD_PRIMARY_KEY:
+          case DROP_PRIMARY_KEY:
+          case ADD_COLUMN_WITH_VOLATILE_DEFAULT:
           case ATTACH_PARTITION:
             return "SELECT a FROM " + tableName + " WHERE a = 1";
           case DETACH_PARTITION: