refactor: sql-tools (#19717)

server/src/sql-tools/readers/index.reader.ts

@@ -0,0 +1,58 @@
+import { sql } from 'kysely';
+import { DatabaseReader } from 'src/sql-tools/types';
+
+export const readIndexes: DatabaseReader = async (schema, db) => {
+  const indexes = await db
+    .selectFrom('pg_index as ix')
+    // matching index, which has column information
+    .innerJoin('pg_class as i', 'ix.indexrelid', 'i.oid')
+    .innerJoin('pg_am as a', 'i.relam', 'a.oid')
+    // matching table
+    .innerJoin('pg_class as t', 'ix.indrelid', 't.oid')
+    // namespace
+    .innerJoin('pg_namespace', 'pg_namespace.oid', 'i.relnamespace')
+    // PK and UQ constraints automatically have indexes, so we can ignore those
+    .leftJoin('pg_constraint', (join) =>
+      join
+        .onRef('pg_constraint.conindid', '=', 'i.oid')
+        .on('pg_constraint.contype', 'in', [sql.lit('p'), sql.lit('u')]),
+    )
+    .where('pg_constraint.oid', 'is', null)
+    .select((eb) => [
+      'i.relname as index_name',
+      't.relname as table_name',
+      'ix.indisunique as unique',
+      'a.amname as using',
+      eb.fn<string>('pg_get_expr', ['ix.indexprs', 'ix.indrelid']).as('expression'),
+      eb.fn<string>('pg_get_expr', ['ix.indpred', 'ix.indrelid']).as('where'),
+      eb
+        .selectFrom('pg_attribute as a')
+        .where('t.relkind', '=', sql.lit('r'))
+        .whereRef('a.attrelid', '=', 't.oid')
+        // list of columns numbers in the index
+        .whereRef('a.attnum', '=', sql`any("ix"."indkey")`)
+        .select((eb) => eb.fn<string[]>('json_agg', ['a.attname']).as('column_name'))
+        .as('column_names'),
+    ])
+    .where('pg_namespace.nspname', '=', schema.schemaName)
+    .where('ix.indisprimary', '=', sql.lit(false))
+    .execute();
+
+  for (const index of indexes) {
+    const table = schema.tables.find((table) => table.name === index.table_name);
+    if (!table) {
+      continue;
+    }
+
+    table.indexes.push({
+      name: index.index_name,
+      tableName: index.table_name,
+      columnNames: index.column_names ?? undefined,
+      expression: index.expression ?? undefined,
+      using: index.using,
+      where: index.where ?? undefined,
+      unique: index.unique,
+      synchronize: true,
+    });
+  }
+};