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A [[Options|local database option]] can also be assigned locally via a pragma. Examples:==BaseX Pragmas==
* Whitespace chopping Many optimizations in BaseX will only be performed if an expression is disabled for a particular document ''deterministic'' (see {{Option|CHOP}}i. e., if it always yields the same output and does not have side effects). By flagging an expression as non-deterministic, optimizations and query rewritings can be suppressed:
</pre>
Many optimizations and query rewritings can be disabled by marking an expression as non-deterministic:
<pre class="brush:xquery">
count( (# basex:non-deterministic #) { 1 to 10 })
→Database Pragmas
=Pragmas=
<pre class="brush:xquery">
sum( (# dbbasex:chop false non-deterministic #) { doc('doc.xml' 1 to 100000000}) }
</pre>
This pragma can be helpful when debugging your code. ==Database Pragmas== All [[Options|local database options]] can be assigned via pragmas. Some examples: * {{Version|9.0}}: Enforce query to be rewritten for index rewriting access. This can e. g. be helpful if the name of a database name is not static (see [[Indexes#Enforce Rewritings|Enforce Rewritings]] for more examples):
<pre class="brush:xquery">
</pre>
* {{Version|9.0}}: Temporarily disable node copying in node constructors (see {{Option|COPYNODE}} for more details). The following query will be evaluated faster, and take much less memory, than without pragma, because the database nodes will not be fully copied, but only attached to the new {{Code|xml}} parent element:
<pre class="brush:xquery">
}
)
</pre>
