Kevin Minder created HIVE-19996:
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Summary: Beeline performance poor with drivers having slow
DatabaseMetaData.getPrimaryKeys impl
Key: HIVE-19996
URL: https://issues.apache.org/jira/browse/HIVE-19996
Project: Hive
Issue Type: Improvement
Components: Beeline
Affects Versions: 1.2.1
Environment: Issue detected using Beeline with HBase Phoenix thin
driver and a result set with many columns.
Reporter: Kevin Minder
Beeline performance is rather poor for table output format when two conditions
occur for the same result set.
# The result set has a large number of columns.
# The driver being used has a slow implementation of
DatabaseMetaData.getPrimaryKeys.
For example testing has shown that for a query with ~100 columns using the
HBase Phoenix thin driver the execution time can be cut from ~30 seconds to ~2
seconds by using CSV output format vs table output format. For example:
{{select * from system.catalog;}}
This is due to how primary keys are detected. Currently the Rows implementation
will make a metadata call for every column to determine it is a primary key for
display purposes. I propose optimizing this such that a metadata call is only
made for each unique table in the result set's columns.
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