Oracle Text Indexing

When oracle rebuilds an text index (CTXCAT,CONTEXT or CTXRULE) it does a full scan to the data, so it should be rebuild only in a certain period (like once a day or twice a day, depending on the application).

You can build/rebuild the index by executing:
SQL> EXEC CTX_DDL.SYNC_INDEX('text_column_idx');
SQL> EXEC CTX_DDL.OPTIMIZE_INDEX('text_column_idx','FULL');

Index optimization can be performed in three modes (FAST, FULL or TOKEN). Êxample used FULL.

You should use this kind of indexes if your information is more or less static (at least you can live with no refreshes to the information during a certain period).