null terminated strings. The FE/BE protocol sends in some cases null
terminated strings to the client. The docs for the FE/BE protocol state
that there is no limit on the size of a null terminated string sent to
the client and a client should be coded using an expanding buffer to
deal with large strings. The old code did not do this and gave an error
if a null terminated string was greater than either 4 or 8K. It appears
that with the advent of TOAST very long SQL statements are becoming more
common, and apparently some error messages from the backend include the
SQL statement thus easily exceeding the 8K limit in the old code.
In fixing I also cleaned up some calls in the JDBC fastpath code that
were not doing character set conversion under multibyte, and removed
some methods that were no longer needed. I also removed a potential
threading problem with a shared variable that was being used in
Connection.java.
Thanks to Steve Wampler for discovering the problem and sending the
initial diffs that were the basis of this patch.
thanks,
--Barry
non-multibyte database loosing 8bit characters. This patch will cause
the jdbc driver to ignore the encoding reported by the database when
multibyte isn't enabled and use the JVM default in that case.
Barry Lind
jdbc/Connection.java
Andy
P.S. in Connection.java if encoding=="WIN" then dbEncoding is set to
"Cp1252".
What if it's Cyrillic "WIN"? Than it should be "Cp1251". Is there any
way to fix that without making different "WIN" encodings in
PostgreSQL?
Andy Rysin
- Fixed bug where Statement.setMaxRows() was a global setting. Now
limited to just itself.
- Changed LargeObject.read(byte[],int,int) to return the actual number
of bytes read (used to be void).
- LargeObject now supports InputStream's!
- PreparedStatement.setBinaryStream() now works!
- ResultSet.getBinaryStream() now returns an InputStream that doesn't
copy the blob into memory first!
- Connection.isClosed() now tests to see if the connection is still alive
rather than if it thinks it's alive.
- Added new error message into errors.properties "postgresql.notsensitive"
This is used by jdbc2.ResultSet when a method is called that should
fetch the current value of a row from the database refreshRow() for
example.
- These methods no longer throw the not implemented but the new noupdate
error. This is in preparation for the Updateable ResultSet support
which will overide these methods by extending the existing class to
implement that functionality, but needed to show something other than
notimplemented:
moveToCurrentRow()
moveToInsertRow()
rowDeleted()
rowInserted()
all update*() methods, except those that took the column as a String
as they were already implemented to convert the String to an int.
- getFetchDirection() and setFetchDirection() now throws
"postgresql.notimp" as we only support one direction.
The CursorResultSet will overide this when its implemented.
- Created a new class under jdbc2 UpdateableResultSet which extends
ResultSet and overides the relevent update methods.
This allows us to implement them easily at a later date.
- In jdbc2.Connection, the following methods are now implemented:
createStatement(type,concurrency);
getTypeMap();
setTypeMap(Map);
- The JDBC2 type mapping scheme almost complete, just needs SQLInput &
SQLOutput to be implemented.
- Removed some Statement methods that somehow appeared in Connection.
- In jdbc2.Statement()
getResultSetConcurrency()
getResultSetType()
setResultSetConcurrency()
setResultSetType()
- Finally removed the old 6.5.x driver.
- These methods in org.postgresql.jdbc2.ResultSet are now implemented:
getBigDecimal(int) ie: without a scale (why did this get missed?)
getBlob(int)
getCharacterStream(int)
getConcurrency()
getDate(int,Calendar)
getFetchDirection()
getFetchSize()
getTime(int,Calendar)
getTimestamp(int,Calendar)
getType()
NB: Where int represents the column name, the associated version
taking a String were already implemented by calling the int
version.
- These methods no longer throw the not implemented but the new noupdate
error. This is in preparation for the Updateable ResultSet support
which will overide these methods by extending the existing class to
implement that functionality, but needed to show something other than
notimplemented:
cancelRowUpdates()
deleteRow()
- Added new error message into errors.properties "postgresql.noupdate"
This is used by jdbc2.ResultSet when an update method is called and
the ResultSet is not updateable. A new method notUpdateable() has been
added to that class to throw this exception, keeping the binary size
down.
- Added new error message into errors.properties "postgresql.psqlnotimp"
This is used instead of unimplemented when it's a feature in the
backend that is preventing this method from being implemented.
- Removed getKeysetSize() as its not part of the ResultSet API
Thu Jan 18 09:46:00 GMT 2001 peter@retep.org.uk
- Applied modified patch from Richard Bullington-McGuire
<rbulling@microstate.com>. I had to modify it as some of the code
patched now exists in different classes, and some of it actually
patched obsolete code.
Wed Jan 17 10:19:00 GMT 2001 peter@retep.org.uk
- Updated Implementation to include both ANT & JBuilder
- Updated README to reflect the changes since 7.0
- Created jdbc.jpr file which allows JBuilder to be used to edit the
source. JBuilder _CAN_NOT_ be used to compile. You must use ANT for
that. It's only to allow JBuilders syntax checking to improve the
drivers source. Refer to Implementation for more details
added to support character set encodings. However I noticed that the
encoding that is used isn't obtained from the DB. Since Java uses
unicode UCS2 internally the character set encoding is used to translate
strings from/to the DB encoding. So it seems logical that the code
would get the encoding from the DB instead of the current method of
requiring the user pass it as a parameter.
Attached is a patch that gets the DB encoding from the DB in the same
manner as is done in libpq/fe-connect.c. The patch is created off of
the latest CVS sources (Connection.java version 1.10).
Barry Lind
couldn't produce a full patch using cvs diff -c this time since I have
created new files and anonymous cvs usage doesn't allow you to
adds. I'm supplying the modified src/interfaces/jdbc as a tarball at :
http://www.candleweb.no/~gunnar/projects/pgsql/postgres-jdbc-2000-10-05.tgz
The new files that should be added are :
? org/postgresql/PGStatement.java
? org/postgresql/ObjectPool.java
? org/postgresql/ObjectPoolFactory.java
There is now a global static pool of free byte arrays and used byte arrays
connected to a statement object. This is the role of the new PGStatement
class. Access to the global free array is synchronized, while we rely on
the PG_Stream synchronization for the used array.
My measurements show that the perfomance boost on this code is not quite as
big as my last shot, but it is still an improvement. Maybe some of the
difference is due to the new synchronization on the global array. I think I
will look into choosing between on a connection level and global level.
I have also started experimented with improving the performance of the
various conversions. The problem here is ofcourse related handle the
various encodings. One thing I found to speed up ResultSet.getInt() a lot
was to do custom conversion on the byte array into int instead of going
through the getString() to do the conversion. But I'm unsure if this is
portable, can we assume that a digit never can be represented by more than
one byte ? It works fine in my iso-latin-8859-1 environment, but what about
other environments ? Maybe we could provide different ResultSet
implementations depending on the encoding used or delegate some methods of
the result set to an "converter class".
Check the org/postgresql/jdbc2/FastResultSet.java in the tarball above to
see the modified getInt() method.
Regards,
Gunnar
Fixed Statement, so that the update count is valid when an SQL DELETE operation is done.
While fixing the update count, made it easier to get the OID of the last insert as well. Example is in example/basic.java
file containing the latest version of the JDBC driver, allowing it to be
compiled and used under JDK 1.2 and later.
NB: None (well almost none) of the new methods actually do anything. This
release only handles getting it to compile and run. Now this is done, I'll
start working on implementing the new stuff.
Now this tar file replaces everything under src/interfaces/jdbc. I had to
do it this way, rather than diffs, because most of the classes under the
postgresql subdirectory have moved to a new directory under that one, to
enable the support of the two JDBC standards.
Here's a list of files in the tar file. Any file not listed here (in the
postgresql directory) will have to be deleted, otherwise it could cause
the driver to fail:
Peter Mount
important step towards making the driver compliant, and means that for
some Java applications and servlets, only a single database connection
is
needed, so in a sence this is a nice little show stopper for 6.4 (and
should still be backward compatible to 6.3.2).
Peter
This fixes a problem in ResultSet.getDate() when the column is NULL
(reported by Vincent Partington <Vincent.Partington@nmg.nl>)
And fixes a problem with Field's (ResultSet.getObject() was proving to be
slow as it repetedly send queries for oid -> name mapping - fixed by
creating a cache. (reported by Mario Ellebrecht <ellebrec@nads.de>)
This patch fixes the following:
* Fixes minor bug found in DatabaseMetaData.getTables() where it doesn't
handle default table types.
* It now reports an error if the client opens a database using
properties, and either the user or password properties are missing. This
should make the recent problem with Servlets easier to find.
* Commented out obsolete property in Driver.getPropertyInfo()
[This is a repost - it supercedes the previous one. It fixes the patch so
it doesn't bread aix port, plus there's a file missing out of the
original post because difforig doesn't pick up new files. It's now
attached. peter]
This patch brings the JDBC driver up to the current protocol spec.
Basically, the backend now tells the driver what authentication scheme to
use.
The patch also fixes a performance problem with large objects. In the
buffer manager, each fastpath call was sending multiple Notifications to
the backend (sometimes more data in the form of notifications were being
sent than blob data!).
Bruce Momjian