During the years I have a lot of times encountered performance problems that ended up to be fast queries (less than 10ms) which are executed very much. In these situations the execution plans, from such queries can look like:

 

OPERATION            OPTIONS                 OBJECT# NAME                         -------------------- -------------------- ---------- ----------------------------------- SELECT STATEMENT                                     .                           SORT                 ORDER BY                        .                           TABLE ACCESS         BY INDEX ROWID           120713 XXX.TABLE_WITH_MANY_COLUMNS INDEX                RANGE SCAN               121558 XXX.INDEX_WITH_FEW_COLUMNS 

 

In a lot of cases we deal with a query for example which is returning fewer columns than exists in the involved table like four, from an involved table having twenty columns. Although the execution plan looks already pretty “OK”, it still results in a query which is in top three most resource taking queries.

 

To enhance the query we can use “Fat Indexes” or nowadays better known “Tapio Indexes” (I call them like that nowadays). What are these kind of indexes…. In More >