1. Database Reference
  2. Dynamic Performance Views
  3. Dynamic Performance (V$) Views: V$IM_COLUMN_LEVEL to V$RULE_SET_AGGREGATE_STATS
  4. V$PQ_SESSTAT

9.127 V$PQ_SESSTAT

V$PQ_SESSTAT lists session statistics for parallel queries.

After you have run a query or DML operation, you can use the information derived from V$PQ_SESSTAT to view the number of PX (Parallel Execution) servers used, and other information for the session and system.

Column Datatype Description

STATISTIC

VARCHAR2(30)

Name of the statistic:

  • Queries Parallelized - Number of queries run in parallel

  • DDL Parallelized - Number of DDL operations run in parallel

  • DML Parallelized - Number of DML operations run in parallel

  • DFO Trees - Number of executed DFO trees

  • DOP - Degree of parallelism used for the last statement

  • Servers - Maximum number of PX servers used at the same time

  • Allocation Height - Requested number of PX servers per instance

  • Allocation Width - Requested number of instances

  • Local Msgs Sent - Number of local (intra-instance) messages sent

  • Distr Msgs Sent - Number of remote (inter-instance) messages sent

  • Local Msgs Recv'd - Number of local (intra-instance) messages received

  • Distr Msgs Recv'd - Number of remote (inter-instance) messages received

  • Server Sets - Maximum number of PX server sets used at the same time for the last statement

  • Total Servers Released - Total number of PX servers acquired and released

  • Servers Released Early - Total number of PX servers released proactively

  • Server Sets Released Early - Total number of PX server sets released proactively

LAST_QUERY

NUMBER

Value of the statistic for the last operation

SESSION_TOTAL

NUMBER

Value of the statistic for the entire session to this point in time

The value of the statistic for the entire session to this point in time is not maintained for the DOP, Servers, Allocation Height, Allocation Width, Server Sets, Total Servers Released, Servers Released Early, and Server Sets Released Early statistics.

CON_ID

NUMBER

The ID of the container to which the data pertains. Possible values include:

  • 0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.

  • 1: This value is used for rows containing data that pertain to only the root

  • n: Where n is the applicable container ID for the rows containing data