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| author | Bruce Momjian <bruce@momjian.us> | 2009-02-06 18:18:54 +0000 |
|---|---|---|
| committer | Bruce Momjian <bruce@momjian.us> | 2009-02-06 18:18:54 +0000 |
| commit | 3d1a1eeddb24580b5b3d6fc0e50a68d467696d49 (patch) | |
| tree | 59b5526d8ad5667cae83e833f058290acaa726d0 | |
| parent | 8c78f8e65c2f68e946f145770cf24a49ac88c891 (diff) | |
Document ways to avoid libpq WSACleanup() overhead on Windows.
Andrew Chernow
| -rw-r--r-- | doc/src/sgml/libpq.sgml | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml index 0a4379a76b9..75a0e3edd53 100644 --- a/doc/src/sgml/libpq.sgml +++ b/doc/src/sgml/libpq.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/libpq.sgml,v 1.275 2009/01/10 20:14:30 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/libpq.sgml,v 1.276 2009/02/06 18:18:54 momjian Exp $ --> <chapter id="libpq"> <title><application>libpq</application> - C Library</title> @@ -63,6 +63,21 @@ The <function>PQstatus</> function should be called to check whether a connection was successfully made before queries are sent via the connection object. + + <note> + <para> + On Windows, there is a way to improve performance if a single + database connection is repeated started and shutdown. Internally, + libpq calls WSAStartup() and WSACleanup() for connection startup + and shutdown, respectively. WSAStartup() increments an internal + Windows library reference count which is decremented by WSACleanup(). + When the reference count is just one, calling WSACleanup() frees + all resources and all DLLs are unloaded. This is an expensive + operation. To avoid this, an application can manually call + WSAStartup() so resources will not be freed when the last database + connection is closed. + </para> + </note> <variablelist> <varlistentry> |