libpq is reentrant and
thread-safe by default. You might need to use special compiler
command-line options when you compile your application code.
Refer to your system's documentation for information about how to
build thread-enabled applications, or look in
PTHREAD_LIBS. This function allows the querying
of libpq's thread-safe
One thread restriction is that no two threads attempt to
manipulate the same
at the same time. In particular, you cannot issue concurrent
commands from different threads through the same connection
object. (If you need to run concurrent commands, use multiple
PGresult objects are normally
read-only after creation, and so can be passed around freely
between threads. However, if you use any of the
PGresult-modifying functions described in
Section 34.11 or
Section 34.13, it's up to you
to avoid concurrent operations on the same
The deprecated functions
PQoidStatus are not thread-safe and should not
be used in multithread programs.
PQrequestCancel can be replaced by
PQoidStatus can be replaced by
If you are using Kerberos inside your application (in addition
to inside libpq), you will need
to do locking around Kerberos calls because Kerberos functions
are not thread-safe. See function
PQregisterThreadLock in the libpq source code for a way to do
cooperative locking between libpq and your application.
If you experience problems with threaded applications, run the
src/tools/thread to see
if your platform has thread-unsafe functions. This program is run
configure, but for binary
distributions your library might not match the library used to
build the binaries.
If you see anything in the documentation that is not correct, does not match your experience with the particular feature or requires further clarification, please use this form to report a documentation issue.