$hist_table_access_n

The $hist_table_access_n table records the table access history for a query. This table becomes enabled whenever history type is Table.

Table 1. $hist_table_access_n
Name Type Description
npsid integer This value along with the npsInstanceId and opid form the foreign key into the operation table.
npsinstanceid integer Instance ID of the source 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 and the NPS ID (npsid) and instance ID (npsinstanceid) form:
  • A foreign key into the hist_log_entry_n table
  • A primary key for this table
seqid integer A plain sequence number of the entry. It starts at zero for every npsid, npsinstanceid, and opid. It increments monotonically for table access records for each query.
sessionid bigint Session ID. This ID with NPS ID (npsid) and instance ID (npsinstanceid) form the foreign key from query, plan, table, and column access tables into session tables.
dbid bigint OID of the database where the table is defined
dbname nvarchar(128) The name of the database where the table is defined
schemaid bigint The OID of the schema as specified in catalog.schema.table
schemaname nvarchar(128) The schema name as specified in catalog.schema.table
tableid bigint The table id of the table
tablename nvarchar(128) The table name of the table
usage integer The following bits are set to true if table appears in:
  • (usage & 1) <> 0 = selected
  • (usage & 2) <> 0 = inserted
  • (usage & 4) <> 0 = deleted
  • (usage & 8) <> 0 = updated
  • (usage & 16) <> 0 = truncated
  • (usage & 32) <> 0 = dropped
  • (usage & 64) <> 0 = created
  • (usage & 128) <> 0 = statsgenerated
  • (usage & 256) <> 0 = locked
  • (usage & 512) <> 0 = altered