Wei Zheng created HIVE-15267:
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Summary: Make query length calculation logic more accurate in
TxnUtils.needNewQuery()
Key: HIVE-15267
URL: https://issues.apache.org/jira/browse/HIVE-15267
Project: Hive
Issue Type: Bug
Components: Hive, Transactions
Affects Versions: 2.1.0, 1.2.1
Reporter: Wei Zheng
Assignee: Wei Zheng
In HIVE-15181 there's such review comment, for which this ticket will handle
{code}
in TxnUtils.needNewQuery() "sizeInBytes / 1024 > queryMemoryLimit" doesn't do
the right thing.
If the user sets METASTORE_DIRECT_SQL_MAX_QUERY_LENGTH to 1K, they most likely
want each SQL string to be at most 1K.
But if sizeInBytes=2047, this still returns false.
It should include length of "suffix" in computation of sizeInBytes
Along the same lines: the check for max query length is done after each batch
is already added to the query. Suppose there are 1000 9-digit txn IDs in each
IN(...). That's, conservatively, 18KB of text. So the length of each query is
increasing in 18KB chunks.
I think the check for query length should be done for each item in IN clause.
If some DB has a limit on query length of X, then any query > X will fail. So I
think this must ensure not to produce any queries > X, even by 1 char.
For example, case 3.1 of the UT generates a query of almost 4000 characters -
this is clearly > 1KB.
{code}
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