AIMMS Knowledge Base Article – KB000015
Filtered reading from the database can be slow
From AIMMS 3.4 to AIMMS 3.5 the reading from a database with filtering can take more time.
Previously, you used AIMMS 3.4 to read from a database with filtering. Now you use AIMMS 3.5 and reading from the same database takes more time.
Filtering is probably the cause of this slower reading from the database. In AIMMS 3.4 (and lower) temporary tables with an index on the columns on which the filtering was done were created in the database. This increased the performance, but because it also required write access on the database, in AIMMS 3.5 the temporary tables are no longer created.
Please check whether the primary keys in the database table, on which the filtering takes place, are indexed. If this is not the case, specify an index on these primary keys and try to read again. Primary keys in Access database tables do not have an index by default; primary keys in Oracle database tables do have a primary key by default.
You should also consider whether you really need the filtering. Filtering is only necessary when you want to read part of the information from a database table, based on the information available in AIMMS. If you always read all data from the table, you could remove the filtering statement, which will make the reading from the database go faster.
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