[jira] [Created] (HIVE-24367) Explore whether HiveAlterHandler::alterTable can be optimised for non-partitioned tablesInbox

["Rajesh Balamohan (Jira)" <ji...@apache.org>]

Rajesh Balamohan created HIVE-24367:
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             Summary: Explore whether HiveAlterHandler::alterTable can be optimised for non-partitioned tablesInbox
                 Key: HIVE-24367
                 URL: https://issues.apache.org/jira/browse/HIVE-24367
             Project: Hive
          Issue Type: Improvement
          Components: HiveServer2
            Reporter: Rajesh Balamohan


{color:#222222}Writing lots of delta in non-partitioned table creates runtime issues, when lot of delta folders are present.{color}

{color:#222222} {color}

{color:#222222}Following code in HiveAlterHandler is invoked for every insert operation. It computes {{{color}

{color:#222222}updateTableStatsSlow}} for every insert causing runtime delays.{color}

{color:#222222} {color}
{noformat}
if (MetaStoreUtils.requireCalStats(null, null, newt, environmentContext) &&
    !isPartitionedTable) {
  Database db = msdb.getDatabase(catName, newDbName);
  assert(isReplicated == HiveMetaStore.HMSHandler.isDbReplicationTarget(db));
  // Update table stats. For partitioned table, we update stats in alterPartition()
  MetaStoreUtils.updateTableStatsSlow(db, newt, wh, false, true, environmentContext);
}
{noformat}
{color:#222222}It would be good to explore whether only the newly added delta can be listed for computing stats. This would avoid huge listing call during stats collection.{color}

{color:#222222}e.g queries to repro{color}
{noformat}
CREATE TABLE IF NOT EXISTS test (name String, value int);
INSERT INTO test VALUES('K1',1);
INSERT INTO test VALUES('K2',2);
..
..
..
INSERT INTO test VALUES('K20000',2)

 {noformat}
 



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