What releases should the jdbc driver support? Was: Speedup patch for getTables() and getIndexInfo()

We have been trying to remain backwardly compatible back to 7.0. But as
you point out some non-backwardly compatible things have been added. It
is possible to use outer-joins for 7.1 and greater and not use them for
7.0 (i.e. if (connection.haveMinimumServerVersion("7.1")) { do join
stuff } else { do existing logic } ). But before doing that does anyone
have an opinion on how far back the driver should support server versions?

I would suggest we have a policy of supporting the current and two
previous versions. Since the current production version is 7.2 that
means supporting 7.0 and 7.1 in the 7.2 driver, and supporting 7.1 and
7.2 in the 7.3 driver. The problem with this is that we generally don't
backport fixes to previous releases, so if someone found a bug in the
7.2 driver and was running on a 7.0 database they wouldn't be able to
easily get a fix since we would fix it in the 7.3 version which wouldn't
support 7.0. If we decide on a policy I think it is then a good idea to
have the driver error when connecting to a database version that isn't
supported.

thanks,
--Barry

Panu Outinen wrote:
> At 10:00 12.9.2002 -0400, Dave Cramer wrote:
>
>> Panu,
>>
>> The getIndexInfo uses an outer join which won't be backward compatible?
>> I did apply the getTables patch and will commit soon, can you modify the
>> getIndexInfo part?
>
>
> Well, both getTables() and getIndexInfo() part of my patch need the
> 'outer join' functionality. And e.g. getColumns() uses 'outer join'
> always in current code!
>
> So how far backward compatible does it need to be nowadays ? I mean 7.3
> version of Postgresql is already coming, isn't 7.1.x enough ?
>
> - Panu
>
>
>
>> Dave
>> On Sun, 2002-09-08 at 14:18, Panu Outinen wrote:
>> > Hi !!
>> >
>> > The following patch speeds up the queries in getTables() and
>> > getIndexInfo(). It replaces the looping of queries with a simple join
>> > operation. Patch is against the current CVS (2002-09-08).
>> >
>> > - Panu
>> >
>> > PS. Tested against PostgreSQL 7.1.2 and PostgreSQL 7.2.1 databases
>> >
>> >
>>
--------------------------------------------------------------------------
>>
>> >
>> > --- AbstractJdbc1DatabaseMetaData.java.org Sun Sep 8 20:58:57 2002
>> > +++ AbstractJdbc1DatabaseMetaData.java Sun Sep 8 21:02:58 2002
>> > @@ -1836,7 +1836,9 @@
>> > f[4] = new Field(connection, "REMARKS", iVarcharOid,
>> NAME_SIZE);
>> >
>> > // Now form the query
>> > - StringBuffer sql = new StringBuffer("select
>> relname,oid,relkind from
>> > pg_class where (");
>> > + StringBuffer sql = new
>> > StringBuffer(connection.haveMinimumServerVersion("7.2") ?
>> > + "select
>> relname,oid,relkind,obj_description(oid,'pg_class') from
>> > pg_class where (" :
>> > + "select c.relname,c.oid,c.relkind,d.description from
>> pg_class c
>> > left outer join pg_description d on (d.objoid = c.oid) where (" );
>> >
>> > boolean notFirst = false;
>> > for (int i = 0;i < types.length;i++)
>> > @@ -1863,24 +1865,6 @@
>> > while (r.next())
>> > {
>> > byte[][] tuple = new byte[5][0];
>> > -
>> > - // Fetch the description for the table (if any)
>> > - String getDescriptionStatement =
>> > -
>> connection.haveMinimumServerVersion("7.2") ?
>> > - "select obj_description(" +
>> r.getInt(2) + ",'pg_class')" :
>> > - "select description from
>> pg_description where objoid=" + r.getInt(2);
>> > -
>> > - java.sql.ResultSet dr =
>> connection.ExecSQL(getDescriptionStatement);
>> > -
>> > - byte remarks[] = null;
>> > -
>> > - if
>> (((AbstractJdbc1ResultSet)dr).getTupleCount() == 1)
>> > - {
>> > - dr.next();
>> > - remarks = dr.getBytes(1);
>> > - }
>> > - dr.close();
>> > -
>> > String relKind;
>> > switch (r.getBytes(3)[0])
>> > {
>> > @@ -1911,7 +1895,7 @@
>> > tuple[1] = null; // Schema name
>> > tuple[2] = r.getBytes(1); // Table name
>> > tuple[3] = (relKind == null) ? null :
>> relKind.getBytes(); // Table type
>> > - tuple[4] = remarks; // Remarks
>> > + tuple[4] = r.getBytes(4); //Remarks
>> > v.addElement(tuple);
>> > }
>> > r.close();
>> > @@ -3096,8 +3080,8 @@
>> >
"x.indkey, " +
>> >
>> "c.reltuples, " +
>> >
>> "c.relpages, " +
>> > -
>> "x.indexrelid " +
>> > - "FROM
>> pg_index x, pg_class c, pg_class i, pg_am a " +
>> > +
"b.attname " +
>> > + "FROM
>> pg_index x left outer join pg_attribute b on (x.indexrelid
>> > = b.attrelid), pg_class c, pg_class i, pg_am a " +
>> > "WHERE
>> ((c.relname = '" + tableName.toLowerCase() + "') " +
>> > " AND
>> (c.oid = x.indrelid) " +
>> > " AND
>> (i.oid = x.indexrelid) " +
>> > @@ -3118,7 +3102,6 @@
>> > {
>> > columnOrdinals[o++] =
>> Integer.parseInt(stok.nextToken());
>> > }
>> > - java.sql.ResultSet columnNameRS =
>> connection.ExecSQL("select a.attname
>> > FROM pg_attribute a WHERE a.attrelid = " + r.getInt(9));
>> > for (int i = 0; i < columnOrdinals.length; i++)
>> > {
>> > byte [] [] tuple = new byte [13] [];
>> > @@ -3134,14 +3117,7 @@
>> >
Integer.toString(java.sql.DatabaseMetaData.tableIndexHashed).getBytes()
>> > :
>> >
Integer.toString(java.sql.DatabaseMetaData.tableIndexOther).getBytes();
>> > tuple[7] = Integer.toString(i +
>> 1).getBytes();
>> > - if (columnNameRS.next())
>> > - {
>> > - tuple[8] =
>> columnNameRS.getBytes(1);
>> > - }
>> > - else
>> > - {
>> > - tuple[8] = "".getBytes();
>> > - }
>> > + tuple[8] = r.getBytes(9);
>> > tuple[9] = null; // sort sequence ???
>> > tuple[10] = r.getBytes(7); //
>> inexact
>> > tuple[11] = r.getBytes(8);
>> >
>> >
>> >
>> >
>> >
>> >
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