The EXPLAIN_STREAM table represents the input and output data streams between individual operators and data objects. The data objects themselves are represented in the EXPLAIN_OBJECT table. The operators involved in a data stream are to be found in the EXPLAIN_OPERATOR table.
|Column Name||Data Type||Nullable?||Key?||Description|
|EXPLAIN_REQUESTER||VARCHAR(128)||No||FK||Authorization ID of initiator of this Explain request.|
|EXPLAIN_TIME||TIMESTAMP||No||FK||Time of initiation for Explain request.|
|SOURCE_NAME||VARCHAR(128)||No||FK||Name of the package running when the dynamic statement was explained or name of the source file when the static SQL was explained.|
|SOURCE_SCHEMA||VARCHAR(128)||No||FK||Schema, or qualifier, of source of Explain request.|
|SOURCE_VERSION||VARCHAR(64)||No||FK||Version of the source of the Explain request.|
|EXPLAIN_LEVEL||CHAR(1)||No||FK||Level of Explain information for which this row is relevant.|
|STMTNO||INTEGER||No||FK||Statement number within package to which this explain information is related.|
|SECTNO||INTEGER||No||FK||Section number within package to which this explain information is related.|
|STREAM_ID||INTEGER||No||No||Unique ID for this data stream within the specified operator.|
|SOURCE_TYPE||CHAR(1)||No||No||Indicates the source of this data stream:
|SOURCE_ID||SMALLINT||No||No||Unique ID for the operator within this query that is the source of this data stream. Set to -1 if SOURCE_TYPE is 'D'.|
|TARGET_TYPE||CHAR(1)||No||No||Indicates the target of this data stream:
|TARGET_ID||SMALLINT||No||No||Unique ID for the operator within this query that is the target of this data stream. Set to -1 if TARGET_TYPE is 'D'.|
|OBJECT_SCHEMA||VARCHAR(128)||Yes||No||Schema to which the affected data object belongs. Set to null if both SOURCE_TYPE and TARGET_TYPE are 'O'.|
|OBJECT_NAME||VARCHAR(128)||Yes||No||Name of the object that is the subject of data stream. Set to null if both SOURCE_TYPE and TARGET_TYPE are 'O'.|
|STREAM_COUNT||DOUBLE||No||No||Estimated cardinality of data stream.|
|COLUMN_COUNT||SMALLINT||No||No||Number of columns in data stream.|
|PREDICATE_ID||INTEGER||No||No||If this stream is part of a subquery for a predicate, the predicate ID will be reflected here, otherwise the column is set to -1.|
|COLUMN_NAMES||CLOB(2M)||Yes||No||This column contains the names and ordering information of the columns involved in this
These names will be in the format of:
Where (A) indicates a column in ascending order, (D) indicates a column in descending order, and no ordering information indicates that either the column is not ordered or ordering is not relevant.
|PMID||SMALLINT||No||No||Distribution map ID.|
|SINGLE_NODE||CHAR(5)||Yes||No||Indicates whether this data stream is on a single or on multiple database partitions:
|PARTITION_COLUMNS||CLOB(2M)||Yes||No||List of the columns on which this data stream is distributed.|
|SEQUENCE_SIZES||CLOB(2M)||Yes||No||Lists the expected sequence size for XML columns, or shows "NA" (not applicable) for any
non-XML columns in the data stream.
Set to null if there is not at least one XML column in the data stream.