diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/func.sgml | 4 | ||||
| -rw-r--r-- | doc/src/sgml/jit.sgml | 29 |
2 files changed, 17 insertions, 16 deletions
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 9d1772f349a..a11f3abc822 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -15945,8 +15945,8 @@ SELECT * FROM pg_ls_dir('.') WITH ORDINALITY AS t(ls,n); <row> <entry><literal><function>pg_jit_available()</function></literal></entry> <entry><type>boolean</type></entry> - <entry>is <acronym>JIT</acronym> available in this session (see <xref - linkend="jit"/>)? Returns <literal>false</literal> if <xref + <entry>is <acronym>JIT</acronym> compilation available in this session + (see <xref linkend="jit"/>)? Returns <literal>false</literal> if <xref linkend="guc-jit"/> is set to false.</entry> </row> diff --git a/doc/src/sgml/jit.sgml b/doc/src/sgml/jit.sgml index ece259b5b4b..2a647e8c6c5 100644 --- a/doc/src/sgml/jit.sgml +++ b/doc/src/sgml/jit.sgml @@ -18,7 +18,7 @@ </para> <sect1 id="jit-reason"> - <title>What is <acronym>JIT</acronym>?</title> + <title>What is <acronym>JIT</acronym> compilation?</title> <para> Just-in-time compilation (<acronym>JIT</acronym>) is the process of turning @@ -33,7 +33,7 @@ <para> <productname>PostgreSQL</productname> has builtin support to perform - <acronym>JIT</acronym> using <ulink + <acronym>JIT</acronym> compilation using <ulink url="https://llvm.org/"><productname>LLVM</productname></ulink> when <productname>PostgreSQL</productname> was built with <literal>--with-llvm</literal> (see <xref linkend="configure-with-llvm"/>). @@ -97,15 +97,15 @@ <title>When to <acronym>JIT</acronym>?</title> <para> - <acronym>JIT</acronym> is beneficial primarily for long-running CPU bound - queries. Frequently these will be analytical queries. For short queries - the overhead of performing <acronym>JIT</acronym> will often be higher than - the time it can save. + <acronym>JIT</acronym> compilation is beneficial primarily for long-running + CPU bound queries. Frequently these will be analytical queries. For short + queries the added overhead of performing <acronym>JIT</acronym> compilation + will often be higher than the time it can save. </para> <para> - To determine whether <acronym>JIT</acronym> is used, the total cost of a - query (see <xref linkend="planner-stats-details"/> and <xref + To determine whether <acronym>JIT</acronym> compilation is used, the total + cost of a query (see <xref linkend="planner-stats-details"/> and <xref linkend="runtime-config-query-constants"/>) is used. </para> @@ -117,9 +117,9 @@ <para> If the planner, based on the above criterion, decided that - <acronym>JIT</acronym> is beneficial, two further decisions are + <acronym>JIT</acronym> compilation is beneficial, two further decisions are made. Firstly, if the query is more costly than the <xref - linkend="guc-jit-optimize-above-cost"/>, GUC expensive optimizations are + linkend="guc-jit-optimize-above-cost"/> GUC, expensive optimizations are used to improve the generated code. Secondly, if the query is more costly than the <xref linkend="guc-jit-inline-above-cost"/> GUC, short functions and operators used in the query will be inlined. Both of these operations @@ -187,8 +187,9 @@ SET └─────────────────────────────────────────────────────────────────────────────────────────────────────────────┘ </programlisting> As visible here, <acronym>JIT</acronym> was used, but inlining and - optimization were not. If <xref linkend="guc-jit-optimize-above-cost"/>, - <xref linkend="guc-jit-inline-above-cost"/> were lowered, just like <xref + expensive optimization were not. If <xref + linkend="guc-jit-optimize-above-cost"/>, <xref + linkend="guc-jit-inline-above-cost"/> were lowered, just like <xref linkend="guc-jit-above-cost"/>, that would change. </para> </sect1> @@ -197,8 +198,8 @@ SET <title>Configuration</title> <para> - <xref linkend="guc-jit"/> determines whether <acronym>JIT</acronym> is - enabled or disabled. + <xref linkend="guc-jit"/> determines whether <acronym>JIT</acronym> + compilation is enabled or disabled. </para> <para> |