IBM PureData System for Analytics, Version 7.1
IBM PureData System for Analytics, Version 7.1
The $hist_plan_prolog_n table records the plan history information. This data is collected at the beginning of the plan execution. This table becomes enabled whenever history type is Plan.
| Name | Type | Description |
|---|---|---|
| npsid | integer | This value along with the instance ID (npsInstanceId) and operation ID (opid) form the foreign key into the query table. |
| npsinstanceid | integer | Instance ID of the source IBM® Netezza® system. |
| opid | bigint | Operation ID. Used as a foreign key from query epilog, overflow and plan, table, column access tables to query prolog. |
| logentryid | bigint | This ID is a foreign key into the hist_log_entry_n table with the NPS ID (npsid) and instance ID (npsinstanceid). This ID with npsid and npsinstanceid is also a primary key for this table. |
| sessionid | bigint | Session ID. This ID, together with the NPS ID (npsid) and instance ID (npsinstanceid) form the foreign key from query, plan, table, and column access tables into session tables. |
| planid | integer | Plan ID. This is used to make an equi join in addition to NPS ID (npsid), instance ID (npsinstanceid), and operation ID (opid) to match a plan prolog to a plan epilog record. |
| xid | bigint | DBOS transaction ID. |
| gkpriority | integer | This field is deprecated and is no longer used. |
| submittime | timestamp | Submit time of the plan. |
| queuetime | timestamp | This field is deprecated and is no longer used. |
| preptime | timestamp | Date and time when the first snippet is prepared. |
| gratime | timestamp | Time when the plan is queued to GRA. |
| starttime | Start time of plan execution. | |
| ismainplan | Flag for the main plan of a query. | |
| estimatedcost | The estimated cost of the plan. | |
| estimateddisk | bigint | The estimated disk space of the plan. |
| estimatedmem | bigint | The estimated memory of the plan. |
| totalsnippets | integer | The total number of snippets. |
| signature | bigint | The signature of the plan, which is stored as a checksum value. If two plans have the same signature, especially for the same query, the plans are most likely identical. |
| qcrestart | integer | The count of query restart after a state change. The value is zero if a restart has not occurred. |
| tzoffset | integer | The timezone offset in minutes. This field is available only in database version 2 or later. |