Definition
==========
Implement the SET PATH statement.
```
SET PATH 'schema1, schema2, schema3';
```
Function
--------
In MariaDB, the SQL-path will also be used to lookup packages in
package routine invocations, so the following script:
SET PATH 'sys';
SELECT UTL_ENCODE.BASE64_DECODE('data');
invokes SYS.UTL_ENCODE.BASE64_DECODE('data'), i.e. the function
BASE64_DECODE() in the packge UTL_ENCODE in the database SYS
(if such package and package routine exist).
MariaDB implementation details
------------------------------
The ticket's requirement stated the grammar should support delimited
identifiers with backticks or double quotes within the string quote,
ie: the single tick. A simple parser was implemented to handle this
requirement in Sql_path::from_text.
Only 16 schemas are supported per session - we do not want too many
schemas in the path anyway since it will impact performance. This also
means that the path cache is a simple static array for easier memory
management.
The existing syntax for CREATE SERVER
CREATE [OR REPLACE] SERVER [IF NOT EXISTS] server_name
FOREIGN DATA WRAPPER wrapper_name
OPTIONS (option [, option] ...)
option:
{ HOST character-literal
| DATABASE character-literal
| USER character-literal
| PASSWORD character-literal
| SOCKET character-literal
| OWNER character-literal
| PORT numeric-literal }
With this change we have:
option:
{ HOST character-literal
| DATABASE character-literal
| USER character-literal
| PASSWORD character-literal
| SOCKET character-literal
| OWNER character-literal
| PORT numeric-literal
| PORT quoted-numerical-literal
| identifier character-literal}
We store these options as a JSON field in the mysql.servers system
table. We retain the restriction that PORT needs to be a number, but
also allow it to be a quoted number, so that SHOW CREATE SERVER can be
used for dumping. Without an accompanied implementation of SHOW CREATE
SERVER, some mysqldump tests will fail. Therefore this commit should
be immediately followed by the one implementating SHOW CREATE SERVER,
with testing covering both.
The limit of socket length on unix according to libc is 108, see
sockaddr_un::sun_path, but in the table it is a string of max length
64, which results in truncation of socket and failure to connect by
plugins using servers such as spider.
These are mainly internal files so is a low impact change.
The few scripts/mysql*sql where renames to mariadb_* prefix
on the name.
mysql-test renamed to mariadb-test in the final packages
