Which table HiveMetaStoreClient.getPartition queries and does that table have index on partitions

hiveanalysis.md

This code is exectuted to get parition list

private MPartition getMPartition(String dbName, String tableName, List<String> part_vals)
     .........
     ........
     query =
          pm.newQuery(MPartition.class,
              "table.tableName == t1 && table.database.name == t2 && partitionName == t3");
      query.declareParameters("java.lang.String t1, java.lang.String t2, java.lang.String t3");
      mparts = (List<MPartition>) query.execute(tableName, dbName, name);
      pm.retrieveAll(mparts);
      commited = commitTransaction();

Here MPartition class in mapped to table and we are doing

select * from where "table.tableName == t1 && table.database.name == t2 && partitionName == t3"

which table maps to MPartition ? Hive uses datanucleus - jdo orm framework to talk to db , so package.jdo maps java class to db table

<class name="MPartition" table="PARTITIONS" identity-type="datastore" detachable="true">
      <index name="UniquePartition" unique="true">
        <column name="PART_NAME"/>
        <column name="TBL_ID"/>
      </index>
      <datastore-identity>
        <column name="PART_ID"/>
      </datastore-identity>
      <field name="partitionName">

This shows PARTITIONS table has index on PART_NAME and TBL_ID

desc PARTITIONS;
+------------------+--------------+--------+-------+-----------+---------+
| Field            | Type         | Null   | Key   |   Default | Extra   |
|------------------+--------------+--------+-------+-----------+---------|
| PART_ID          | bigint(20)   | NO     | PRI   |    <null> |         |
| CREATE_TIME      | int(11)      | NO     |       |    <null> |         |
| LAST_ACCESS_TIME | int(11)      | NO     |       |    <null> |         |
| PART_NAME        | varchar(767) | YES    | MUL   |    <null> |         |
| SD_ID            | bigint(20)   | YES    | MUL   |    <null> |         |
| TBL_ID           | bigint(20)   | YES    | MUL   |    <null> |         |
| LINK_TARGET_ID   | bigint(20)   | YES    | MUL   |    <null> |         |
+------------------+--------------+--------+-------+-----------+---------+

SHOW INDEX FROM PARTITIONS;
+------------+--------------+-----------------+----------------+----------------+-------------+---------------+------------+----------+--------+--------------+-----------+-----------------+
| Table      |   Non_unique | Key_name        |   Seq_in_index | Column_name    | Collation   |   Cardinality |   Sub_part |   Packed | Null   | Index_type   | Comment   | Index_comment   |
|------------+--------------+-----------------+----------------+----------------+-------------+---------------+------------+----------+--------+--------------+-----------+-----------------|
| PARTITIONS |            0 | PRIMARY         |              1 | PART_ID        | A           |        215346 |     <null> |   <null> |        | BTREE        |           |                 |
| PARTITIONS |            0 | UNIQUEPARTITION |              1 | PART_NAME      | A           |        215346 |     <null> |   <null> | YES    | BTREE        |           |                 |
| PARTITIONS |            0 | UNIQUEPARTITION |              2 | TBL_ID         | A           |        215346 |     <null> |   <null> | YES    | BTREE        |           |                 |
| PARTITIONS |            1 | PARTITIONS_N49  |              1 | TBL_ID         | A           |           159 |     <null> |   <null> | YES    | BTREE        |           |                 |
| PARTITIONS |            1 | PARTITIONS_N50  |              1 | SD_ID          | A           |        215346 |     <null> |   <null> | YES    | BTREE        |           |                 |
| PARTITIONS |            1 | PARTITIONS_N51  |              1 | LINK_TARGET_ID | A           |             2 |     <null> |   <null> | YES    | BTREE        |           |                 |
+------------+--------------+-----------------+----------------+----------------+-------------+---------------+------------+----------+--------+--------------+-----------+-----------------+