Feature: new PGPOOL SET CACHE DELETE command.

The new PGPOOl SET command allows to delete query cache by specifying
the previous query used to create the query cache entry. example usage
is:

PGPOOL SET CACHE DELETE 'SELECT * FROM t1;'

This command is particularly useful for queries that are not
invalidated by the auto cache invalidation feature because the query
does not have any reference to tables.

diff --git a/doc.ja/src/sgml/ref/allfiles.sgml b/doc.ja/src/sgml/ref/allfiles.sgml
index 6764e8f9cd30e2c86632cf9055c3fda30e5b6097..89be154bc1d2e5ab293f0d8d8dc680a8332fce58 100644 (file)
--- a/doc.ja/src/sgml/ref/allfiles.sgml
+++ b/doc.ja/src/sgml/ref/allfiles.sgml
@@ -30,6 +30,7 @@ Complete list of usable sgml source files in this directory.
 <!ENTITY pgpoolShow          SYSTEM "pgpool_show.sgml">
 <!ENTITY pgpoolReset         SYSTEM "pgpool_reset.sgml">
 <!ENTITY pgpoolSet           SYSTEM "pgpool_set.sgml">
+<!ENTITY pgpoolSetCache      SYSTEM "pgpool_set_cache.sgml">
 <!ENTITY showPoolStatus      SYSTEM "show_pool_status.sgml">
 <!ENTITY showPoolNodes       SYSTEM "show_pool_nodes.sgml">
 <!ENTITY showPoolProcesses   SYSTEM "show_pool_processes.sgml">

diff --git a/doc.ja/src/sgml/ref/pgpool_set_cache.sgml b/doc.ja/src/sgml/ref/pgpool_set_cache.sgml
new file mode 100644 (file)
index 0000000..82f0235
--- /dev/null
+++ b/doc.ja/src/sgml/ref/pgpool_set_cache.sgml
@@ -0,0 +1,131 @@
+<!--
+doc/src/sgml/ref/set.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="SQL-PGPOOL-SET-CACHE">
+ <indexterm zone="sql-pgpool-set-cache">
+  <primary>PGPOOL SET</primary>
+ </indexterm>
+
+ <refmeta>
+  <refentrytitle>PGPOOL SET CACHE</refentrytitle>
+  <manvolnum>1</manvolnum>
+  <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+  <refname>PGPOOL SET CACHE</refname>
+<!--
+  <refpurpose>delete query cache</refpurpose>
+-->
+  <refpurpose>クエリキャッシュを削除する</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+  <synopsis>
+   PGPOOL SET CACHE DELETE <replaceable class="PARAMETER">'query'</replaceable>
+  </synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+<!--
+  <title>Description</title>
+-->
+  <title>説明</title>
+
+  <para>
+<!--
+   The <command>PGPOOL SET CACHE DELETE</command> command deletes the
+   <link linkend="runtime-in-memory-query-cache">query cache</link>
+   previously created by the query. The query string must be exactly
+   identical to the previous query, including
+   trailing <literal>';'</literal>. Nevertheless if the query
+   includes <literal>'</literal> (single quore), it needs to be
+   prefixed by <literal>'</literal> like:
+-->
+   <command>PGPOOL SET CACHE DELETE</command>コマンドは、以前のクエリで作成された<link linkend="runtime-in-memory-query-cache">クエリキャッシュ</link>を削除します。
+   クエリ文字列は、末尾の<literal>';'</literal>も含めて以前のクエリと完全に一致していなければなりません。
+   にもかかわらず、<literal>'</literal> (単一引用符)がクエリに含まれている場合は、以下のように<literal>'</literal>を前に追加する必要があります。
+   <programlisting>
+PGPOOL SET CACHE DELETE 'SELECT ''FOO'';';
+   </programlisting>
+<!--
+   This command is particularly useful for queries that are not
+   invalidated by
+   the <link linkend="guc-memqcache-auto-cache-invalidation">auto
+   cache invalidation feature</link> because the query does not have
+   any reference to tables.
+-->
+   このコマンドはとりわけ、クエリ中にテーブル参照を含んでいないために<link linkend="guc-memqcache-auto-cache-invalidation">自動キャッシュ削除機能</link>で削除されないクエリに有用です。
+  </para>
+  <para>
+<!--
+   If you do not remember the previous query, you can
+   use <xref linkend="PCP-INVALIDATE-QUERY-CACHE"> to delete all the
+   query cache including the cache you want to delete. However it
+   requires the <productname>Pgpool-II</productname> admin privilege.
+-->
+    以前のクエリが思い出せない時は、<xref linkend="PCP-INVALIDATE-QUERY-CACHE">を使って、削除したいクエリキャッシュも含み、すべてのクエリキャッシュを削除することができます。
+    ただし、これは<productname>Pgpool-II</productname>の管理者権限が必要になります。
+  </para>
+  <para>
+<!--
+   Upon successful deletion of the query cache, this command emits a
+   notice message:
+-->
+   クエリキャッシュの削除に成功すると、以下のNOTICEメッセージを表示します。
+   <programlisting>
+NOTICE:  query cache deleted. query: "<literal>query string</literal>"
+   </programlisting>
+<!--
+   If the cache does not exist or query cache is not enabled, it emits
+   a notice message:
+-->
+   クエリキャッシュが存在しないか、クエリキャッシュが無効の場合には、以下のNOTICEメッセージを表示します。
+   <programlisting>
+NOTICE:  query cache does not exist for query: "<literal>query string</literal>"
+   </programlisting>
+  </para>
+ </refsect1>
+
+ <refsect1>
+<!--
+  <title>Examples</title>
+-->
+  <title>例</title>
+
+  <para>
+<!--
+   Accidentally created an unwanted query cache. Delete it by using
+   the command.
+-->
+   間違って希望しないクエリキャッシュを作成してしまいました。
+   以下のコマンドで削除します。
+    <programlisting>
+test=# /*FORCE QUERY CACHE*/SELECT current_timestamp;
+       current_timestamp       
+-------------------------------
+ 2024-10-18 18:25:07.826423+09
+(1 row)
+
+test=# PGPOOL SET CACHE DELETE '/*FORCE QUERY CACHE*/SELECT current_timestamp;';
+NOTICE:  query cache deleted. query: "/*FORCE QUERY CACHE*/SELECT current_timestamp;"
+SET
+    </programlisting>
+  </para>
+
+ </refsect1>
+
+ <refsect1>
+<!--
+  <title>See Also</title>
+-->
+  <title>関連項目</title>
+
+  <simplelist type="inline">
+   <member><xref linkend="PCP-INVALIDATE-QUERY-CACHE"></member>
+  </simplelist>
+ </refsect1>
+
+</refentry>

diff --git a/doc.ja/src/sgml/reference.sgml b/doc.ja/src/sgml/reference.sgml
index 548b05f24b17f7d8adef443e7cdad485f9f11a8a..adfe8e1e18f8c8474e158c951188fd5ac8244b2a 100644 (file)
--- a/doc.ja/src/sgml/reference.sgml
+++ b/doc.ja/src/sgml/reference.sgml
@@ -222,6 +222,7 @@
 
   &pgpoolShow
   &pgpoolSet
+  &pgpoolSetCache
   &pgpoolReset
   &showPoolStatus
   &showPoolNodes

diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml
index 6764e8f9cd30e2c86632cf9055c3fda30e5b6097..89be154bc1d2e5ab293f0d8d8dc680a8332fce58 100644 (file)
--- a/doc/src/sgml/ref/allfiles.sgml
+++ b/doc/src/sgml/ref/allfiles.sgml
@@ -30,6 +30,7 @@ Complete list of usable sgml source files in this directory.
 <!ENTITY pgpoolShow          SYSTEM "pgpool_show.sgml">
 <!ENTITY pgpoolReset         SYSTEM "pgpool_reset.sgml">
 <!ENTITY pgpoolSet           SYSTEM "pgpool_set.sgml">
+<!ENTITY pgpoolSetCache      SYSTEM "pgpool_set_cache.sgml">
 <!ENTITY showPoolStatus      SYSTEM "show_pool_status.sgml">
 <!ENTITY showPoolNodes       SYSTEM "show_pool_nodes.sgml">
 <!ENTITY showPoolProcesses   SYSTEM "show_pool_processes.sgml">

diff --git a/doc/src/sgml/ref/pgpool_set_cache.sgml b/doc/src/sgml/ref/pgpool_set_cache.sgml
new file mode 100644 (file)
index 0000000..8ae8d42
--- /dev/null
+++ b/doc/src/sgml/ref/pgpool_set_cache.sgml
@@ -0,0 +1,97 @@
+<!--
+doc/src/sgml/ref/set.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="SQL-PGPOOL-SET-CACHE">
+ <indexterm zone="sql-pgpool-set-cache">
+  <primary>PGPOOL SET</primary>
+ </indexterm>
+
+ <refmeta>
+  <refentrytitle>PGPOOL SET CACHE</refentrytitle>
+  <manvolnum>1</manvolnum>
+  <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+  <refname>PGPOOL SET CACHE</refname>
+  <refpurpose>delete query cache</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+  <synopsis>
+   PGPOOL SET CACHE DELETE <replaceable class="PARAMETER">'query'</replaceable>
+  </synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+  <title>Description</title>
+
+  <para>
+   The <command>PGPOOL SET CACHE DELETE</command> command deletes the
+   <link linkend="runtime-in-memory-query-cache">query cache</link>
+   previously created by the query. The query string must be exactly
+   identical to the previous query, including
+   trailing <literal>';'</literal>. Nevertheless if the query
+   includes <literal>'</literal> (single quore), it needs to be
+   prefixed by <literal>'</literal> like:
+   <programlisting>
+PGPOOL SET CACHE DELETE 'SELECT ''FOO'';';
+   </programlisting>
+   This command is particularly useful for queries that are not
+   invalidated by
+   the <link linkend="guc-memqcache-auto-cache-invalidation">auto
+   cache invalidation feature</link> because the query does not have
+   any reference to tables.
+  </para>
+  <para>
+   If you do not remember the previous query, you can
+   use <xref linkend="PCP-INVALIDATE-QUERY-CACHE"> to delete all the
+   query cache including the cache you want to delete. However it
+   requires the <productname>Pgpool-II</productname> admin privilege.
+  </para>
+  <para>
+   Upon successful deletion of the query cache, this command emits a
+   notice message:
+   <programlisting>
+NOTICE:  query cache deleted. query: "<literal>query string</literal>"
+   </programlisting>
+   If the cache does not exist or query cache is not enabled, it emits
+   a notice message:
+   <programlisting>
+NOTICE:  query cache does not exist for query: "<literal>query string</literal>"
+   </programlisting>
+  </para>
+ </refsect1>
+
+ <refsect1>
+  <title>Examples</title>
+
+  <para>
+   Accidentally created an unwanted query cache. Delete it by using
+   the command.
+    <programlisting>
+test=# /*FORCE QUERY CACHE*/SELECT current_timestamp;
+       current_timestamp       
+-------------------------------
+ 2024-10-18 18:25:07.826423+09
+(1 row)
+
+test=# PGPOOL SET CACHE DELETE '/*FORCE QUERY CACHE*/SELECT current_timestamp;';
+NOTICE:  query cache deleted. query: "/*FORCE QUERY CACHE*/SELECT current_timestamp;"
+SET
+    </programlisting>
+  </para>
+
+ </refsect1>
+
+ <refsect1>
+  <title>See Also</title>
+
+  <simplelist type="inline">
+   <member><xref linkend="PCP-INVALIDATE-QUERY-CACHE"></member>
+  </simplelist>
+ </refsect1>
+
+</refentry>

diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml
index ffc7ddb8674be8f48600d8ea5017558cea627a28..2b2db4947cc8404b038cc71b036f50da210d6da4 100644 (file)
--- a/doc/src/sgml/reference.sgml
+++ b/doc/src/sgml/reference.sgml
@@ -155,6 +155,7 @@
 
   &pgpoolShow
   &pgpoolSet
+  &pgpoolSetCache
   &pgpoolReset
   &showPoolStatus
   &showPoolNodes

diff --git a/src/include/parser/nodes.h b/src/include/parser/nodes.h
index 734faa48f348a90c2f8f9b4a3bcd932e8ea6bb84..1d5bb3ed627a6b20a7f8c54641cbb99fa88b48ef 100644 (file)
--- a/src/include/parser/nodes.h
+++ b/src/include/parser/nodes.h
@@ -34,6 +34,7 @@ typedef enum NodeTag
        /* pgpool Extension */
                                T_PgpoolVariableSetStmt,
                                T_PgpoolVariableShowStmt,
+                               T_PgpoolQueryCacheStmt,
 #include "nodetags.h"
 } NodeTag;
 

diff --git a/src/include/query_cache/pool_memqcache.h b/src/include/query_cache/pool_memqcache.h
index 5a0a1fce92573b701c494b7a55c281196e8e5392..042121fc4d0fef11912f58bbe5319c3fe5cd6fbd 100644 (file)
--- a/src/include/query_cache/pool_memqcache.h
+++ b/src/include/query_cache/pool_memqcache.h
@@ -307,4 +307,6 @@ extern void pool_init_whole_cache_blocks(void);
 
 extern void clear_query_cache(void);
 
+extern bool query_cache_delete_by_stmt(char *query, POOL_CONNECTION_POOL * backend);
+
 #endif                                                 /* POOL_MEMQCACHE_H */

diff --git a/src/parser/gram.y b/src/parser/gram.y
index a39f98991740638d25b68080f3205088415914df..61663cce2ea8ea4de1a56dae70e68594ab75738e 100644 (file)
--- a/src/parser/gram.y
+++ b/src/parser/gram.y
@@ -1655,6 +1655,13 @@ VariableSetStmt:
                                        n->is_local = false;
                                        $$ = (Node *) n;
                                }
+                       | PGPOOL set_rest_more
+                               {
+                                       VariableSetStmt *n = $2;
+                                       n->type = T_PgpoolQueryCacheStmt; /* Hack to keep changes minimum */
+                                       n->is_local = false;
+                                       $$ = (Node *) n;
+                               }
                        | SET set_rest
                                {
                                        VariableSetStmt *n = $2;
@@ -1834,6 +1841,13 @@ set_rest_more:   /* Generic SET syntaxes: */
                                        n->args = list_make1(makeStringConst($3, @3));
                                        $$ = n;
                                }
+                       /* PGPOOL CACHE DELETE */
+                       | SET CACHE DELETE_P Sconst
+                               {
+                                       VariableSetStmt *n = makeNode(VariableSetStmt);
+                                       n->name = $4;   /* query to delete query cache */
+                                       $$ = n;
+                               }
                ;
 
 var_name:      ColId                                                           { $$ = $1; }

diff --git a/src/protocol/pool_proto_modules.c b/src/protocol/pool_proto_modules.c
index df8d27e0ca957bf2140ca534fbdc486695d97757..4988325dcad1de1379dc45f174e6df51d6a37392 100644 (file)
--- a/src/protocol/pool_proto_modules.c
+++ b/src/protocol/pool_proto_modules.c
@@ -450,7 +450,20 @@ SimpleQuery(POOL_CONNECTION * frontend,
                        pool_set_skip_reading_from_backends();
                        return POOL_CONTINUE;
                }
+               if (IsA(node, PgpoolQueryCacheStmt))
+               {
+                       VariableSetStmt *vnode = (VariableSetStmt *) node;
 
+                       if (query_cache_delete_by_stmt(vnode->name, backend))
+                               elog(NOTICE, "query cache deleted. query: \"%s\"", vnode->name);
+                       else
+                               elog(NOTICE, "query cache does not exist for query: \"%s\"", vnode->name);
+                       pool_ps_idle_display(backend);
+                       send_complete_and_ready(frontend, backend, "SET", -1);
+                       pool_query_context_destroy(query_context);
+                       pool_set_skip_reading_from_backends();
+                       return POOL_CONTINUE;
+               }
                if (IsA(node, PgpoolVariableSetStmt))
                {
                        VariableSetStmt *vnode = (VariableSetStmt *) node;

diff --git a/src/query_cache/pool_memqcache.c b/src/query_cache/pool_memqcache.c
index 4c55f0fc404a0a26a1742671e6ebefe12e77c407..7f824fe2277fd2487964479c08e6e48460e5c811 100644 (file)
--- a/src/query_cache/pool_memqcache.c
+++ b/src/query_cache/pool_memqcache.c
@@ -4731,3 +4731,56 @@ InvalidateQueryCache(int tableoid, int dboid)
        pool_semaphore_unlock(QUERY_CACHE_STATS_SEM);
        POOL_SETMASK(&oldmask);
 }
+
+/*
+ * Public API to invalidate query cache specified by query string.  Returns
+ * true for successfully query cache invalidation.  If the query cache was not
+ * found, returns false.  Note that this function does not remove any entry in
+ * a table oid file.  That may leave a garbage in the file (which is ignored
+ * by the auto cache invalidation) but it's not worth the trouble to remove
+ * the entry since it's relatively expensive. It needs to rewrite the whole
+ * file in the worst case.
+ */
+bool query_cache_delete_by_stmt(char *query, POOL_CONNECTION_POOL * backend)
+{
+       bool            rtn = true;
+       pool_sigset_t oldmask;
+
+       char            key[MAX_KEY];
+       POOL_CACHEID *cacheid;
+
+       POOL_SETMASK2(&BlockSig, &oldmask);
+       pool_shmem_lock(POOL_MEMQ_EXCLUSIVE_LOCK);
+
+       /* encode md5key */
+       encode_key(query, key, backend);
+
+       if (pool_is_shmem_cache())
+
+       {
+               POOL_QUERY_HASH         hashkey;
+
+               memcpy(hashkey.query_hash, key, POOL_MD5_HASHKEYLEN);
+               cacheid = pool_hash_search(&hashkey);
+               if (cacheid == NULL)
+                       rtn = false;
+               else
+                       pool_delete_item_shmem_cache(cacheid);
+       }
+#ifdef USE_MEMCACHED
+       else
+       {
+               if (delete_cache_on_memcached(key) == 0)
+                       rtn = false;
+       }
+#else
+       {
+               ereport(WARNING,
+                               (errmsg("failed to delete query cache on memcached, memcached support is not enabled")));
+       }
+#endif
+       pool_semaphore_unlock(QUERY_CACHE_STATS_SEM);
+       POOL_SETMASK(&oldmask);
+
+       return rtn;
+}