Can the autoindex feature be disabled?
SangGyu Jeong asked whether the optimizer's automatic index could be disabled for a customer on 12.10.FC6WE. Gaurav Kumar said it cannot be disabled and suggested adding a permanent index; he also noted temp dbspaces are tried first for building it. Eric Rowell knew of no setting, suggested asking support, and said the FULL directive can avoid it. No parameter was found.
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Hi, I would like to know if there is a way to prevent autoindex from being constructed when executing a query. ------------------------------ SangGyu Jeong Software Engineer Infrasoft Seoul Korea, Republic of ------------------------------ #Informix
Hi SangGyu, As far as I know, we can not disable that because it was created automatically by optimizer. If the query plan includes an autoindex path to a large table, you can generally improve performance by adding an index on that column. If you perform a query regularly, you can save time by creating a permanent index. If you perform the query occasionally, you can reasonably let the database server build and discard an index. And may I know the version you are running or you are asking this question in general? ------------------------------ Gaurav Kumar ------------------------------
Hi Gaurav, My customer is using version 12.10.FC6WE. They want to know how to avoid automatic index creation when certain queries are executed. I know that the autoindex feature cannot be controlled, but I just wanted to know if there are any related parameters. They'd better tune the query (or use directives) or create an index.. ------------------------------ SangGyu Jeong Software Engineer Infrasoft Seoul Korea, Republic of ------------------------------
Hi SangGyu, The current algorithm checks for temp dbspaces first. If none of the temp dbspaces provides enough space to hold that table the database dbspace or even the rootdbs is chosen as last resort ------------------------------ Gaurav Kumar ------------------------------
I'm not aware of any, maybe ask support. I know this can be avoided by using a directive (FULL). ------------------------------ ~~~~~~~~~ Eric Rowell ------------------------------