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copied!<p>Since you explain (in a comment) that all the attributes are strings, you may have a hard time improving the situation. You're doing a <strong>lot</strong> of string comparisons in that fetch-- 46k records multiplied by at least 3 for the first two predicates, plus more depending on how many <code>stories</code> relationships there are on average. That's the main reason for your performance issues-- doing that many string comparisons is going to be a bottleneck.</p> <p>A couple of things that may help:</p> <ul> <li>In the third predicate you're looking at <code>@"(ANY stories.permission.owner_person_uid == %@ OR stories.@count == 0)"</code>. Predicates are evaluated left to right. Numeric comparisons are faster than string comparisons, so put the <code>@count</code> check first. If it's true then the second half won't need to be evaluated, and you'll skip a whole lot of string comparisons.</li> <li>The left-to-right thing also applies to the order of your <code>NSPredicate</code> instances. You probably have some idea what the data looks like-- make sure that the <strong>most restrictive</strong> predicate (i.e. the one that the largest number of objects will <em>not</em> pass) is the first one in the list. Then the second-most restrictive, etc. Since you're and-ing the predicates together, an instance fails the first predicate won't need to be checked against the others. Filter out objects as early as possible in the predicate chain.</li> </ul> <p>Probably the easiest gain is by changing the order in the third predicate and then moving it to the front of the list.</p>

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