fix: optimize getMicroblocks query (#1179)

* refactor: optimized query for getMicroblocks

* test: updated tx with microblock

* refactor: changed the query

* refactor: removed unnecessary query check

* fix: resolved lint error

Author: MHassanTariq

src/datastore/pg-store.ts

@@ -563,22 +563,13 @@ export class PgStore {
       const microblockQuery = await sql<
         (MicroblockQueryResult & { tx_id?: string | null; tx_index?: number | null })[]
       >`
-        SELECT microblocks.*, tx_id FROM (
-          SELECT ${sql(MICROBLOCK_COLUMNS)}
-          FROM microblocks
-          WHERE canonical = true AND microblock_canonical = true
-          ORDER BY block_height DESC, microblock_sequence DESC
-          LIMIT ${args.limit}
-          OFFSET ${args.offset}
-        ) microblocks
-        LEFT JOIN (
-          SELECT tx_id, tx_index, microblock_hash
-          FROM txs
-          WHERE canonical = true AND microblock_canonical = true
-          ORDER BY tx_index DESC
-        ) txs
-        ON microblocks.microblock_hash = txs.microblock_hash
-        ORDER BY microblocks.block_height DESC, microblocks.microblock_sequence DESC, txs.tx_index DESC
+      SELECT microblocks.*, txs.tx_id 
+      FROM microblocks LEFT JOIN txs USING(microblock_hash)
+      WHERE microblocks.canonical = true AND microblocks.microblock_canonical = true AND 
+        txs.canonical = true AND txs.microblock_canonical = true
+      ORDER BY microblocks.block_height DESC, microblocks.microblock_sequence DESC, txs.tx_index DESC
+      LIMIT ${args.limit}
+      OFFSET ${args.offset};
       `;
       const microblocks: { microblock: DbMicroblock; txs: string[] }[] = [];
       microblockQuery.forEach(row => {

src/tests/api-tests.ts

@@ -10847,6 +10847,33 @@ describe('api tests', () => {
     expect(result.body.txs).toHaveLength(1);
     expect(result.body.txs[0]).toEqual(tx_id);
   });
+  test('/microblock', async () => {
+    const microblock_hash = '0x0fff';
+    const block = new TestBlockBuilder({ block_hash: '0x1234', block_height: 1 }).build();
+    await db.update(block);
+
+    const microblock = new TestMicroblockStreamBuilder()
+      .addMicroblock({ microblock_hash, parent_index_block_hash: block.block.index_block_hash })
+      .addTx({
+        tx_id: '0xffff',
+      })
+      .addTx({
+        tx_id: '0x1234',
+        canonical: false,
+        microblock_canonical: false,
+      })
+      .build();
+    await db.updateMicroblocks(microblock);
+    const microblockResult = await supertest(api.server).get(`/extended/v1/microblock/`);
+    const response = microblockResult.body;
+    const expectedTxs = ['0xffff'];
+
+    expect(response.total).toEqual(1);
+    expect(response.results).toHaveLength(1);
+    expect(response.results[0].microblock_hash).toEqual(microblock_hash);
+    expect(response.results[0].txs).toHaveLength(1);
+    expect(response.results[0].txs).toEqual(expectedTxs);
+  });
 
   test('/block', async () => {
     const block_hash = '0x1234',