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https://issues.apache.org/jira/browse/SPARK-38230?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Coal Chan updated SPARK-38230:
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Description:
In `org.apache.spark.sql.execution.datasources.
InsertIntoHadoopFsRelationCommand`, `
sparkSession.sessionState.catalog.listPartitions
` will call method `org.apache.hadoop.hive.metastore.listPartitionsPsWithAuth`
of hive metastore client, this method will produce multiple queries per
partition on hive metastore db. When you insert into a table which has too many
partitions(ie: 10k), it will produce too many queries on hive metastore db(ie:
n * 10k = 10nk), it puts a lot of strain on the database.
In fact, it calls method `listPartitions` in order to get locations of
partitions and get `customPartitionLocations`. But in most cases, we do not
have custom partitions, so we can just get partition names.
was:
In `org.apache.spark.sql.execution.datasources.
InsertIntoHadoopFsRelationCommand`, `
sparkSession.sessionState.catalog.listPartitions
` will call method `org.apache.hadoop.hive.metastore.listPartitionsPsWithAuth`
of hive metastore client, this method will produce multiple queries on hive
metastore db. When you insert into a table which has too many partitions(ie:
10k), it will produce too many queries on hive metastore db(ie: n * 10k =
10nk), it puts a lot of strain on the database.
In fact, it calls method `listPartitions` in order to get locations of
partitions and get `customPartitionLocations`. But in most cases, we do not
have custom partitions, so we can just get partition names.
> InsertIntoHadoopFsRelationCommand unnecessarily fetches details of partitions
> in most cases
> -------------------------------------------------------------------------------------------
>
> Key: SPARK-38230
> URL: https://issues.apache.org/jira/browse/SPARK-38230
> Project: Spark
> Issue Type: Improvement
> Components: SQL
> Affects Versions: 3.0.2
> Reporter: Coal Chan
> Priority: Major
>
> In `org.apache.spark.sql.execution.datasources.
> InsertIntoHadoopFsRelationCommand`, `
> sparkSession.sessionState.catalog.listPartitions
> ` will call method
> `org.apache.hadoop.hive.metastore.listPartitionsPsWithAuth` of hive metastore
> client, this method will produce multiple queries per partition on hive
> metastore db. When you insert into a table which has too many partitions(ie:
> 10k), it will produce too many queries on hive metastore db(ie: n * 10k =
> 10nk), it puts a lot of strain on the database.
> In fact, it calls method `listPartitions` in order to get locations of
> partitions and get `customPartitionLocations`. But in most cases, we do not
> have custom partitions, so we can just get partition names.
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