Optimize funding index update query (#1061)

Author: Christopher-Li

indexer/packages/postgres/src/stores/funding-index-updates-table.ts

@@ -193,9 +193,17 @@ export async function findFundingIndexMap(
       options,
     );
 
+  // Assuming block time of 1 second, this should be 4 hours of blocks
+  const FOUR_HOUR_OF_BLOCKS = Big(3600).times(4);
   const fundingIndexUpdates: FundingIndexUpdatesFromDatabase[] = await baseQuery
     .distinctOn(FundingIndexUpdatesColumns.perpetualId)
     .where(FundingIndexUpdatesColumns.effectiveAtHeight, '<=', effectiveBeforeOrAtHeight)
+    // Optimization to reduce number of rows needed to scan
+    .where(
+      FundingIndexUpdatesColumns.effectiveAtHeight,
+      '>',
+      Big(effectiveBeforeOrAtHeight).minus(FOUR_HOUR_OF_BLOCKS).toFixed(),
+    )
     .orderBy(FundingIndexUpdatesColumns.perpetualId)
     .orderBy(FundingIndexUpdatesColumns.effectiveAtHeight, Ordering.DESC)
     .returning('*');