Using LIKE3 for Index Only Search (No Post-Search)

In certain special cases, such as static information which does not change at all except under very controlled circumstances easily managed by the system administrator, there may be instances where an index based search with no qualifying linear post-search may be done without losing meaningful responses to entered queries.

This kind of search is completely optimized based on certain defaults which would be known to be acceptable, including:

• All the search items can be keywords (i.e., no special pattern matchers will be used).

• All searches can be done effectively within the length of the field (i.e., the delimiters used to define proximity of search items is the length of the whole text field).

As more often than not maintaining all the above rules is impractical, dispensing with the post-search would not be done very frequently. However, in some circumstances where these rules fit, the search requirements are narrow, and speed is of the essence, the post-search can be eliminated for optimization purposes.

Texis will examine the query given to LIKE, and if it can guarantee the same results without the post-search it will not perform the post-search, and LIKE will then be equivalent to LIKE3. With these caveats in mind, LIKE3 may be substituted for LIKE in any of the queries illustrated in the previous chapters.