minute and a half to decode a 500Kb on a fairly fast machine. I think the
culprit is sscanf.
I attach a patch that replaces the function with one used to perform the same
task in pyPgSQL (a Python interface to PostgreSQL). This code was written by
Billy Allie, author of pyPgSQL. I've changed a few variable names to match
those in the original code and removed a bit of Pythonness.
Billy has kindly looked at the code and points out that it is slightly
stricter than the original implementation and if it encounters an invalid
bytea such as '\12C' it drops the unescape '\' and outputs '12C'.
The code is licensed by the author under a BSD license.
I've performed limited testing of the function by putting JPEGs into
PostgreSQL, extracting them using them using the new function and diffing
against the original files.
The new function is significantly faster on my machine with the JPEGs being
decoded in less than a second. I attach a modified libpq example program that
I used for my testing.
Ben Lamb.
protocol 3, then falls back to 2 if postmaster rejects the startup packet
with an old-format error message. A side benefit of the rewrite is that
SSL-encrypted connections can now be made without blocking. (I think,
anyway, but do not have a good way to test.)
progress, although all RTs pass using the V3 protocol on a 7.4 database and also pass using the V2 protocol on a 7.3 database.
SSL support is known not to work.
Modified Files:
jdbc/org/postgresql/PGConnection.java
jdbc/org/postgresql/errors.properties
jdbc/org/postgresql/core/BaseConnection.java
jdbc/org/postgresql/core/Encoding.java
jdbc/org/postgresql/core/Field.java
jdbc/org/postgresql/core/PGStream.java
jdbc/org/postgresql/core/QueryExecutor.java
jdbc/org/postgresql/core/StartupPacket.java
jdbc/org/postgresql/fastpath/Fastpath.java
jdbc/org/postgresql/fastpath/FastpathArg.java
jdbc/org/postgresql/jdbc1/AbstractJdbc1Connection.java
jdbc/org/postgresql/test/jdbc2/BlobTest.java
jdbc/org/postgresql/test/jdbc2/CallableStmtTest.java
jdbc/org/postgresql/test/jdbc2/MiscTest.java
jdbc/org/postgresql/test/jdbc3/Jdbc3TestSuite.java
of an index can now be a computed expression instead of a simple variable.
Restrictions on expressions are the same as for predicates (only immutable
functions, no sub-selects). This fixes problems recently introduced with
inlining SQL functions, because the inlining transformation is applied to
both expression trees so the planner can still match them up. Along the
way, improve efficiency of handling index predicates (both predicates and
index expressions are now cached by the relcache) and fix 7.3 oversight
that didn't record dependencies of predicate expressions.
Tom Lane
Bruce Momjian
Michael Meskes
Peter Eisentraut
Barry Lind