Creating Databases With In-Row LOBs

The SAP ASE server uses in-row LOB compression if the table is implicitly or explicitly row- or page-compressed, and, any of the in-row large object columns in the table are implicitly or explicitly LOB compressed.

The in-row size can be as large as the maximum row size allowed in the database. The SAP ASE server lowers the limit on the size of individual column’s in-row LOB storage during inserts and updates, based on the space available for storage in a single page, minus any page or row overheads.

When you create a table in a database where you have specified a valid in-row LOB length database-wide, all LOB columns in the table are created as in-row unless you specify off row in the syntax for the column’s definition. The column’s in-row length, in bytes, is specified by this database-wide setting.

The default value for inrow_lob_length setting is 0 bytes, which causes no changes in behavior to existing databases when you upgrade to SAP ASE version 15.7. Changing this default allows applications with different requirements on in-row storage to control how much LOB data is stored in-row.

The database-wide setting applies only to newly created tables or LOB columns added to existing tables after the database-wide setting is applied or changed. The in-row LOB length inherited by each LOB column when the table was initially created remains unchanged, even when the database-wide setting is altered. To change an individual LOB column’s in-row length or in-row property, use alter table modify column.

To change the default length, use the inrow_lob_length parameter of alter database.