HiveClientImpl¶

:hive-version: 2.3.6 :hadoop-version: 2.10.0 :url-hive-javadoc: https://hive.apache.org/javadocs/r{hive-version}/api :url-hadoop-javadoc: https://hadoop.apache.org/docs/r{hadoop-version}/api

HiveClientImpl is a HiveClient.md[HiveClient] that uses a <> (for meta data/DDL operations using calls to a Hive metastore).

HiveClientImpl is <> exclusively when IsolatedClientLoader is requested to HiveUtils.md#newClientForMetadata[create a new Hive client]. When created, HiveClientImpl is given the location of the default database for the Hive metastore warehouse (i.e. <> that is the value of ../spark-sql-hive-metastore.md#hive.metastore.warehouse.dir[hive.metastore.warehouse.dir] Hive-specific Hadoop configuration property).

NOTE: The location of the default database for the Hive metastore warehouse is /user/hive/warehouse by default.

NOTE: The Hadoop configuration is what HiveExternalCatalog was given when created (which is the default Hadoop configuration from Spark Core's SparkContext.hadoopConfiguration with the Spark properties with spark.hadoop prefix).

[[logging]] [TIP] ==== Enable ALL logging level for org.apache.spark.sql.hive.client.HiveClientImpl logger to see what happens inside.

Add the following line to conf/log4j.properties:

log4j.logger.org.apache.spark.sql.hive.client.HiveClientImpl=ALL

Refer to ../spark-logging.md[Logging].¶

=== [[creating-instance]] Creating HiveClientImpl Instance

HiveClientImpl takes the following to be created:

[[version]] HiveVersion
[[warehouseDir]] Location of the default database for the Hive metastore warehouse if defined (aka warehouseDir)
[[sparkConf]] SparkConf
[[hadoopConf]] Hadoop configuration
[[extraConfig]] Extra configuration
[[initClassLoader]] Initial ClassLoader
[[clientLoader]] IsolatedClientLoader.md[IsolatedClientLoader]

HiveClientImpl initializes the <>.

=== [[client]] Hive Metastore Client -- client Internal Method

[source, scala]¶

client: Hive¶

client is a Hive {url-hive-javadoc}/org/apache/hadoop/hive/ql/metadata/Hive.html[metastore client] (for meta data/DDL operations using calls to the metastore).

=== [[getTableOption]] Retrieving Table Metadata From Hive Metastore -- getTableOption Method

[source, scala]¶

getTableOption( dbName: String, tableName: String): Option[CatalogTable]

NOTE: getTableOption is part of HiveClient.md#getTableOption[HiveClient] contract.

getTableOption prints out the following DEBUG message to the logs:

Looking up [dbName].[tableName]

getTableOption <> and converts the Hive table metadata to Spark's CatalogTable

=== [[renamePartitions]] renamePartitions Method

[source, scala]¶

renamePartitions( db: String, table: String, specs: Seq[TablePartitionSpec], newSpecs: Seq[TablePartitionSpec]): Unit

NOTE: renamePartitions is part of HiveClient.md#renamePartitions[HiveClient Contract] to...FIXME.

renamePartitions...FIXME

=== [[alterPartitions]] alterPartitions Method

[source, scala]¶

alterPartitions( db: String, table: String, newParts: Seq[CatalogTablePartition]): Unit

NOTE: alterPartitions is part of HiveClient.md#alterPartitions[HiveClient Contract] to...FIXME.

alterPartitions...FIXME

=== [[getPartitions]] getPartitions Method

[source, scala]¶

getPartitions( table: CatalogTable, spec: Option[TablePartitionSpec]): Seq[CatalogTablePartition]

NOTE: getPartitions is part of HiveClient.md#getPartitions[HiveClient Contract] to...FIXME.

getPartitions...FIXME

=== [[getPartitionsByFilter]] getPartitionsByFilter Method

[source, scala]¶

getPartitionsByFilter( table: CatalogTable, predicates: Seq[Expression]): Seq[CatalogTablePartition]

NOTE: getPartitionsByFilter is part of HiveClient.md#getPartitionsByFilter[HiveClient Contract] to...FIXME.

getPartitionsByFilter...FIXME

=== [[getPartitionOption]] getPartitionOption Method

[source, scala]¶

getPartitionOption( table: CatalogTable, spec: TablePartitionSpec): Option[CatalogTablePartition]

NOTE: getPartitionOption is part of HiveClient.md#getPartitionOption[HiveClient Contract] to...FIXME.

getPartitionOption...FIXME

=== [[readHiveStats]] Creating Table Statistics from Hive's Table or Partition Parameters -- readHiveStats Internal Method

[source, scala]¶

readHiveStats(properties: Map[String, String]): Option[CatalogStatistics]¶

readHiveStats creates a ../spark-sql-CatalogStatistics.md#creating-instance[CatalogStatistics] from the input Hive table or partition parameters (if available and greater than 0).

.Table Statistics and Hive Parameters [cols="1,2",options="header",width="100%"] |=== | Hive Parameter | Table Statistics

| totalSize | ../spark-sql-CatalogStatistics.md#sizeInBytes[sizeInBytes]

| rawDataSize | ../spark-sql-CatalogStatistics.md#sizeInBytes[sizeInBytes]

| numRows | ../spark-sql-CatalogStatistics.md#rowCount[rowCount] |===

NOTE: totalSize Hive parameter has a higher precedence over rawDataSize for ../spark-sql-CatalogStatistics.md#sizeInBytes[sizeInBytes] table statistic.

NOTE: readHiveStats is used when HiveClientImpl is requested for the metadata of a <> or <>.

=== [[fromHivePartition]] Retrieving Table Partition Metadata (Converting Table Partition Metadata from Hive Format to Spark SQL Format) -- fromHivePartition Method

[source, scala]¶

fromHivePartition(hp: HivePartition): CatalogTablePartition¶

fromHivePartition simply creates a CatalogTablePartition with the following:

spec from Hive's Partition.getSpec if available
storage from Hive's StorageDescriptor of the table partition
parameters from Hive's Partition.getParameters if available
stats from Hive's Partition.getParameters if available and converted to table statistics format

fromHivePartition is used when:

HiveClientImpl is requested for getPartitionOption, getPartitions and getPartitionsByFilter.

Converting Native Table Metadata to Hive's Table¶

toHiveTable(
  table: CatalogTable,
  userName: Option[String] = None): HiveTable

toHiveTable simply creates a new Hive Table and copies the properties from the input CatalogTable.

toHiveTable is used when:

HiveUtils is requested to inferSchema
HiveClientImpl is requested to <>, <>, <>, <>, <>, <> and <>
HiveTableScanExec physical operator is requested for the <>
InsertIntoHiveDirCommand.md[InsertIntoHiveDirCommand] and InsertIntoHiveTable.md[InsertIntoHiveTable] logical commands are executed

=== [[getSparkSQLDataType]] getSparkSQLDataType Internal Utility

[source, scala]¶

getSparkSQLDataType(hc: FieldSchema): DataType¶

getSparkSQLDataType...FIXME

NOTE: getSparkSQLDataType is used when...FIXME

=== [[toHivePartition]] Converting CatalogTablePartition to Hive Partition -- toHivePartition Utility

[source, scala]¶

toHivePartition( p: CatalogTablePartition, ht: Table): Partition

toHivePartition creates a Hive org.apache.hadoop.hive.ql.metadata.Partition for the input CatalogTablePartition and the Hive org.apache.hadoop.hive.ql.metadata.Table.

toHivePartition is used when:

HiveClientImpl is requested to renamePartitions or alterPartitions
HiveTableScanExec physical operator is requested for the raw Hive partitions

=== [[newSession]] Creating New HiveClientImpl -- newSession Method

[source, scala]¶

newSession(): HiveClientImpl¶

NOTE: newSession is part of the HiveClient.md#newSession[HiveClient] contract to...FIXME.

newSession...FIXME

=== [[getRawTableOption]] getRawTableOption Internal Method

[source, scala]¶

getRawTableOption( dbName: String, tableName: String): Option[Table]

getRawTableOption requests the <> for the Hive's {url-hive-javadoc}/org/apache/hadoop/hive/ql/metadata/Table.html[metadata] of the input table.

NOTE: getRawTableOption is used when HiveClientImpl is requested to <> and <>.

Last update: 2021-03-18