Question

I’m planning on generating queries for SQLite that will involve many joins on 12 tables that will surpass the 64 table join limit in SQLite. (~250 table joins or possibly more) This will be running on android eventually. The purpose behind this is to have X amount of user defined fields in the result set depending on the report that is being generated.

Unfortunately I’m not a DBA and I do not know of an optimal way to achieve this.

So far I think the options are:

• Use 2 temp tables to juggle the result set while joining the max amount possible. (My previous solution in SQLServer, fairly slow)
• Produce result sets of a few columns and a key to join on and store them in n temp tables. (Where n is less than 64) Then join all the temp tables on their common key.
• Create a single temp table and fill it up one insert or update at a time.
• Don’t do a big join, perform many selects instead and fill up some sort of data container.

Is there something else I should consider?

Answer 1

Per your comment on Mike’s response, “the query to generate the report needs to join and rejoin many many times”.

Frequently, when dealing with reports, you’ll want to split your query into bite-size chunks, and store intermediary results in temporary tables where applicable.

Also, your question makes it sound like you’ve an entity/attribute/value store and trying to pivot the whole thing. If so, you may want to revisit using this design anti-pattern, since it probably is at the source of your problem.