CakePHP2 - Postgres driver with custom adaptions

This driver was changed in the following ways:

1. The default CakePHP 2.x Postgres driver uses getColumnMeta to infer
   column types from the server. Although the PHP part has been optimized
   in recent years [1], it still incurs an overhead to hit the Postgres
   database on every call with a query like SELECT RELNAME FROM PG_CLASS WHERE OID=... [2]

Thus, this implementation is born which foregoes any use of the meta
data and simply uses PDO::FETCH_ASSOC.

2. There's a problem with special crafted SQL statements which contain the \
   character [3] which actually isn't CakePHP specific but a problem of the
   underlying PDO/PgSQL driver [4].

The method \Postgres::value() was overriden to apply the special C-style
escape operation to strings [5].

3. The default PHP/PDO lastInsertId always returns a string. This driver is
   adapted to return an integer if is_numeric returns true on it. This allows
   easier integration with codebases using strict_types=1.

Requirements and Installation

1. You need at least CakePHP 2.10.12
   
   For CakePHP >= 2.0 and < 2.10.12 , you can use version 0.0.2 of this package
2. Add the line "mfn/cakephp2-postgres-no-meta": "^0.0.6" to your app/composer.json
3. Run php composer.phar require mfn/cakephp2-postgres-no-meta
4. Load the plugin in app/Config/bootstrap.php with the line

CakePlugin::load('PostgresNoMeta');

4. Use the driver in your app/Config/database.php: PostgresNoMeta.Database/PostgresNoMeta (instead of Database/Postgres)
5. Profit!

Rational

During the switch of a big application from MySQL to Postgres it was discovered
that much overhead was lost on Postgres and it was finally discovered that
these meta queries incur a measurable overhead.

The individual queries are very fast but, depending on your queries, they may
add up until a measurable point.

In our case there were performance improvement of up to 50% without any
additional changes except activating this class. YMMV.

A little bit later also found problems with the generated SQL statements, which
in special cases were translated from:

INSERT INTO models(field) VALUES('\'':1');

to

INSERT INTO models(field) VALUES('\''$1');

before sent to the server, causing various problems.

Further reference

• [1] php/php-src#1534
• [2] cakephp/cakephp#6036
• [3] cakephp/cakephp#10373
• [4] https://bugs.php.net/bug.php?id=74220
• [5] https://www.postgresql.org/docs/9.6/static/sql-syntax-lexical.html#SQL-SYNTAX-STRINGS-ESCAPE