Chapter 27. Regression Tests

Table of Contents
27.1. Running the Tests
27.2. Test Evaluation
27.2.1. Error message differences
27.2.2. Locale differences
27.2.3. Date and time differences
27.2.4. Floating-point differences
27.2.5. Row ordering differences
27.2.6. Insufficient stack depth
27.2.7. The "random" test
27.3. Variant Comparison Files

The regression tests are a comprehensive set of tests for the SQL implementation in PostgreSQL. They test standard SQL operations as well as the extended capabilities of PostgreSQL.

27.1. Running the Tests

The regression tests can be run against an already installed and running server, or using a temporary installation within the build tree. Furthermore, there is a "parallel" and a "sequential" mode for running the tests. The sequential method runs each test script in turn, whereas the parallel method starts up multiple server processes to run groups of tests in parallel. Parallel testing gives confidence that interprocess communication and locking are working correctly. For historical reasons, the sequential test is usually run against an existing installation and the parallel method against a temporary installation, but there are no technical reasons for this.

To run the regression tests after building but before installation, type

gmake check

in the top-level directory. (Or you can change to src/test/regress and run the command there.) This will first build several auxiliary files, such as some sample user-defined trigger functions, and then run the test driver script. At the end you should see something like

 All 98 tests passed.

or otherwise a note about which tests failed. See Section 27.2 below before assuming that a "failure" represents a serious problem.

Because this test method runs a temporary server, it will not work when you are the root user (since the server will not start as root). If you already did the build as root, you do not have to start all over. Instead, make the regression test directory writable by some other user, log in as that user, and restart the tests. For example

root# chmod -R a+w src/test/regress
root# chmod -R a+w contrib/spi
root# su - joeuser
joeuser$ cd top-level build directory
joeuser$ gmake check

(The only possible "security risk" here is that other users might be able to alter the regression test results behind your back. Use common sense when managing user permissions.)

Alternatively, run the tests after installation.

If you have configured PostgreSQL to install into a location where an older PostgreSQL installation already exists, and you perform gmake check before installing the new version, you may find that the tests fail because the new programs try to use the already-installed shared libraries. (Typical symptoms are complaints about undefined symbols.) If you wish to run the tests before overwriting the old installation, you'll need to build with configure --disable-rpath. It is not recommended that you use this option for the final installation, however.

The parallel regression test starts quite a few processes under your user ID. Presently, the maximum concurrency is twenty parallel test scripts, which means sixty processes: there's a server process, a psql, and usually a shell parent process for the psql for each test script. So if your system enforces a per-user limit on the number of processes, make sure this limit is at least seventy-five or so, else you may get random-seeming failures in the parallel test. If you are not in a position to raise the limit, you can cut down the degree of parallelism by setting the MAX_CONNECTIONS parameter. For example,

gmake MAX_CONNECTIONS=10 check

runs no more than ten tests concurrently.

On some systems, the default Bourne-compatible shell (/bin/sh) gets confused when it has to manage too many child processes in parallel. This may cause the parallel test run to lock up or fail. In such cases, specify a different Bourne-compatible shell on the command line, for example:

gmake SHELL=/bin/ksh check

If no non-broken shell is available, you may be able to work around the problem by limiting the number of connections, as shown above.

To run the tests after installation (see Chapter 14), initialize a data area and start the server, as explained in Chapter 16, then type

gmake installcheck

or for a parallel test

gmake installcheck-parallel

The tests will expect to contact the server at the local host and the default port number, unless directed otherwise by PGHOST and PGPORT environment variables.

The source distribution also contains regression tests for the optional procedural languages and for some of the contrib modules. At present, these tests can be used only against an already-installed server. To run the tests for all procedural languages that have been built and installed, change to the src/pl directory of the build tree and type

gmake installcheck

You can also do this in any of the subdirectories of src/pl to run tests for just one procedural language. To run the tests for all contrib modules that have them, change to the contrib directory of the build tree and type

gmake installcheck

The contrib modules must have been built and installed first. You can also do this in a subdirectory of contrib to run the tests for just one module.