IMSTAT Procedure

DELETEROWS Statement

The DELETEROWS statement is used to mark rows as deleted, to undelete rows, and to purge rows from an in-memory table. Rows that are marked for deletion or purging are not included in the calculations performed by the server.

Interaction:	If a WHERE clause is active, the rows that meet the criteria are marked for deletion or purging. When no WHERE clause is active, a delete request marks all rows for deletion (they can be undeleted), but the PURGE option removes the rows that are already marked for deletion rather than removing all rows.
Example:	Deleting Rows and Saving a Table to HDFS

Syntax

DELETEROWS Statement Options

Syntax

DELETEROWS </ options>;

DELETEROWS Statement Options

PURGE

specifies to remove from memory the rows that are marked for deletion. The memory that was used by the rows is freed. The purged rows cannot be undeleted. One use case for purging rows is to remove older records from an in-memory table after new records were appended to the table.

If a WHERE clause is active, the rows that meet the criteria are purged. If no WHERE clause is active, then the PURGE request removes the rows that are already marked for deletion. It does not remove all the rows in the table. This was implemented to prevent accidentally removing all rows from a table.

SAVE=table-name

saves the result table so that you can use it in other IMSTAT procedure statements like STORE, REPLAY, and FREE. The value for table-name must be unique within the scope of the procedure execution. The name of a table that has been freed with the FREE statement can be used again in subsequent SAVE= options.

TEMPEXPRESS="SAS-expressions"

TEMPEXPRESS=file-reference

specifies either a quoted string that contains the SAS expression that defines the temporary variables or a file reference to an external file with the SAS statements.

Alias

TE=

TEMPNAMES=variable-name

TEMPNAMES=(variable-list)

specifies the list of temporary variables for the request. Each temporary variable must be defined through SAS statements that you supply with the TEMPEXPRESS= option.

Alias

TN=

UNDELETE

specifies to clear the deletion mark from rows.

If a WHERE clause is active, only the rows that meet the criteria have the deletion mark cleared. A row that has been marked for purging from the table cannot be undeleted.