sql/schemachanger: support partitions and RBR tables for alter PK

Previously, ALTER PRIMARY KEY in the declarative schema changer did not
support partitioned / RBR tables, which would cause it to fallback. This
meant that ALTER PRIMARY KEY would always use the legacy schema changer
on multi-region environments. To address this, this patch adds
partitioning and RBR support into the declarative ALTER PRIMARY KEY.
This includes logic to generate subzone config for replacement indexes
and generating zone configurations for new primary keys.

Fixes: #146725
Release note: None

Author: fqazi

pkg/ccl/partitionccl/zone_test.go

@@ -1022,10 +1022,12 @@ func TestPrimaryKeyChangeZoneConfigs(t *testing.T) {
 	// dropped copy of i2, new copy of i1, and new copy of i2.
 	// These have ID's 2, 3, 6 and 8 respectively.
 	expectedSpans := []roachpb.Key{
-		table.IndexSpan(codec, 2 /* indexID */).Key,
-		table.IndexSpan(codec, 3 /* indexID */).Key,
-		table.IndexSpan(codec, 6 /* indexID */).Key,
-		table.IndexSpan(codec, 8 /* indexID */).Key,
+		table.IndexSpan(codec, 2 /* indexID */).Key, // index: old_i1
+		table.IndexSpan(codec, 3 /* indexID */).Key, // index: old_i2
+		table.IndexSpan(codec, 4 /* indexID */).Key, // index: i1
+		table.IndexSpan(codec, 5 /* indexID */).Key, // index: i1_tmp
+		table.IndexSpan(codec, 6 /* indexID */).Key, // index: i2
+		table.IndexSpan(codec, 7 /* indexID */).Key, // index: i2_tmp
 	}
 	if len(zone.SubzoneSpans) != len(expectedSpans) {
 		t.Fatalf("expected subzones to have length %d", len(expectedSpans))

pkg/ccl/schemachangerccl/ccl_generated_test.go

@@ -0,0 +1,34 @@
+setup
+CREATE DATABASE multiregion_db PRIMARY REGION "us-east1" REGIONS "us-east2", "us-east3" SURVIVE REGION FAILURE;
+CREATE TABLE multiregion_db.public.table_regional_by_row (
+  k INT NOT NULL,
+  V STRING
+) LOCALITY REGIONAL BY ROW;
+CREATE INDEX on multiregion_db.table_regional_by_row(v);
+----
+
+stage-exec phase=PostCommitPhase stage=:
+USE multiregion_db;
+INSERT INTO multiregion_db.table_regional_by_row(k) VALUES($stageKey);
+INSERT INTO  multiregion_db.table_regional_by_row(k) VALUES($stageKey + 1);
+----
+
+stage-exec phase=PostCommitNonRevertiblePhase stage=:
+USE multiregion_db;
+INSERT INTO multiregion_db.table_regional_by_row(k) VALUES($stageKey);
+INSERT INTO multiregion_db.table_regional_by_row(k) VALUES($stageKey + 1);
+----
+
+stage-exec phase=PostCommitPhase stage=:
+USE multiregion_db;
+SELECT crdb_internal.validate_multi_region_zone_configs()
+----
+
+stage-exec phase=PostCommitNonRevertiblePhase stage=:
+USE multiregion_db;
+SELECT crdb_internal.validate_multi_region_zone_configs()
+----
+
+test
+alter table multiregion_db.table_regional_by_row add column m int8 default unique_rowid(), alter primary key using columns(k) USING HASH;
+----