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frank.meulblok
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I'd suggest reading the 10.2A programming handbook chapter on Dynamic queries first: documentation.progress.com/.../wwhelp.htm . Why such an old version of the handbook ? Because one release later the chapter disappeared from the docs entirely and so far it hasn't returned yet. >> What is the limit in the size of a query-prepare statement? The limits to the query where clause are governed by the -inp & -tok parameters - if those are non-default at compile-time you may also need to provide them at runtime. That, and the QUERY-PREPARE() accepts a character type as input, so that'll have the 32k character limit. >> Are there "gotchas" that would prevent the execution plan of QUERY-PREPARE from running the same way as a similar program that is compiled statically? The ones I can think of: - If you're replacing a FOR EACH loop with a query, make sure the query is set to be FORWARD-ONLY. That'll disable the query from using a result list, which in this scenario you won't need and will just waste resources/performance (FOR EACH doesn't use result-lists either and also only goes forward..) - Dynamically prepared queries will select indexes at runtime. For static code, index selection is locked in at compile time. That can trigger differing behavior if you add/change indexes after the code is compiled. (But if you're compiling on the fly anyway, the chances of that happening are basically zero.) - The new server-side joins in OpenEdge 12 currently are only supported by the FOR EACH loops. If you already upgraded, moving to dynamic queries means you'll have to give up the benefits from that for the time being. (Here's hoping we will soon see support for server-side joins for queries too !)
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