Turns out that instead of relying on the Database for a URL, you can set it in the config file, which solves the problem I was having, like so: define(‘WP_SITEURL’,’http://jack.example.com/test_blog/’); and then I set use a different config file for the other instance. soruce: http://codex.wordpress.org/Editing_wp-config.php#WordPress_address_.28URL.29
If your data is inside database as I understand, it is possible to export your database to CSV file and import this to WordPress. CSV file is basically a comma separated list of data from your database that makes it possible to transfer data from different database structure to another. It does indeed take some … Read more
The data is serialized. In order to edit it, you need to unserialize it, edit, then serialize again, and save. You can do that with PHP. Check serialize and unserialize. You can check this tool as well: serializededitor.com
Visit /wp-admin/upgrade.php on each site to manually upgrade the database e.g. http://www.example.com/wp-admin/upgrade.php This happens if you have a site on the WordPress network that doesn’t resolve or if you have spoofed DNS locally but not on the server – your computer knows that www.example.com points at 127.0.0.1 but your local server is still resolving www.example.com … Read more
That table is from the redirection plugin, and isn’t a part of WordPress Core. Deleting it should have no ill effects as long as you disable the plugin too. If you wish to continue using that plugin though, I recommend using the plugin authors support at https://wordpress.org/support/plugin/redirection/
How can I make wordpress suppress mysql errors?
Easiest Way to Authenticate WP Users Using an External DB?
Backup another database with BackUpWordPress plugin [closed]
There’s a plugin called Debug Bar which you can find at http://wordpress.org/plugins/debug-bar/ Don’t leave this enabled in production! But it will tattle on slow MySQL queries. You might also wish to try using WP Clean Up. http://wordpress.org/plugins/wp-clean-up/ This flushes out stale entries in your database, and does a little bit of table reorg/optimization.
There are usually minimal db changes from one version to the next, it should be safe to do the manual-reinstall procedure with 1 older version. You can see the changes it does in wp-admin/includes/upgrade.php