The sysdirectives table stores external optimizer directives that can be applied to queries. Whether queries in client applications can use these optimizer directives depends on the setting of the IFX_EXTDIRECTIVES environment variable on the client system, as described in Chapter 3, and on the EXT_DIRECTIVES setting in the configuration file of the database server.

The sysdirectives table has the following columns:
Table 1. SYSDIRECTIVES table column descriptions
Column Type Explanation
id SERIAL Unique code identifying the optimizer directive
query TEXT Text of the query as it exists in the application
directives TEXT Text of the optimizer directive, without comments
directive_code BYTE Encoded directive
active SMALLINT Integer code that identifies whether this entry is active ( = 1 ) or test only ( = 2 )
hash_code SMALLINT For internal use only

NULL values are not valid in the query column. There is a unique index on the id column.