DB2 10.5 for Linux, UNIX, and Windows

Explain operators

An operator is either an action that must be performed on data, or the output from a table or an index, when the access plan for an SQL or XQuery statement is executed. This section contains a list of the operators that can appear in an access plan graph.

CMPEXP operator
This operator is for debug mode only.
DELETE operator
This operator represents the deletion of rows from a table.
EISCAN operator
This operator scans a user defined index to produce a reduced stream of rows.
FETCH
This operator represents the fetching of columns from a table.
FILTER operator
This operator represents how data is filtered.
GENROW operator
This operator is used by the optimizer to generate rows of data.
GRPBY operator
This operator represents the grouping of rows.
HSJOIN operator
This operator represents hash joins for which the qualified rows from tables are hashed.
INSERT operator
This operator represents the insertion of rows into a table.
IXAND operator
This operator represents the ANDing of the results of multiple index scans.
IXSCAN
This operator represents the scanning of an index.
MGSTREAM operator
This operator represents a multiple distinct aggregation operation.
MSJOIN operator
This operator represents a merge join.
NLJOIN operator
This operator represents a nested loop join.
PIPE operator
This operator is for debug mode only.
REBAL operator
This operator represents the transferal of rows between SMP subagents.
RETURN operator
This operator represents the return of data from a query.
RIDSCN operator
This operator represents the scan of a list of row identifiers (RIDs).
RPD operator
This operator retrieves data from a remote data source.
SHIP operator
This operator retrieves data from a remote data source.
SORT operator
This operator represents the sorting of rows in a table.
TBSCAN operator
This operator represents table scans.
TEMP operator
This operator represents the storage of data in a temporary table.
TQ operator
This operator represents a table queue.
UNION operator
This operator represents the concatenation of steams of rows from multiple tables.
UNIQUE operator
This operator represents rows with duplicate values.
UPDATE operator
This operator represents the updating of data in the rows of a table.
XANDOR operator
This operator allows ANDed predicates to be applied to multiple indexes to reduce underlying table accesses to a minimum.
XISCAN operator
This operation is performed for a single query predicate.
XSCAN operator
This operator is used to navigate XML fragments to evaluate XPath expressions and to extract document fragments if needed.
ZZJOIN operator
This operator represents a zigzag join.