I played a bit with database.

Here is something that looks like Wikipedia database schema but compiles in Posgres (and no, Wikipedia script won't be able to use that yet):

CREATE TABLE user_table ( user_id serial NOT NULL PRIMARY KEY, user_name varchar(255) NOT NULL default '', user_rights varchar(255) NOT NULL default '', user_password varchar(255) NOT NULL default '', user_newpassword varchar(255) NOT NULL default '', user_email varchar(255) NOT NULL default '', user_options varchar(65535) NOT NULL default '', user_newtalk smallint NOT NULL default '1' );

CREATE TABLE cur ( cur_id serial NOT NULL PRIMARY KEY, cur_namespace smallint NOT NULL default '0', cur_title varchar(255) NOT NULL default '', cur_text text NOT NULL default '', cur_comment varchar(255) NOT NULL default '', cur_user int NOT NULL default '0', cur_user_text varchar(255) NOT NULL default '', cur_timestamp char(14) NOT NULL default '', cur_restrictions varchar(255) NOT NULL default '', cur_counter bigint NOT NULL default '0', cur_ind_title varchar(255) NOT NULL default '', cur_ind_text text NOT NULL default '', cur_is_redirect boolean NOT NULL default 'f', cur_minor_edit boolean NOT NULL default 'f', cur_is_new boolean NOT NULL default 'f' );

CREATE TABLE old_table ( old_id serial NOT NULL PRIMARY KEY, old_namespace smallint NOT NULL default '0', old_title varchar(255) NOT NULL default '', old_text text NOT NULL default '', old_comment varchar(255) NOT NULL default '', old_user int NOT NULL default '0', old_user_text varchar(255) NOT NULL, old_timestamp char(14) NOT NULL default '', old_minor_edit boolean NOT NULL default 'f', old_flags varchar(255) NOT NULL default '' );

CREATE TABLE archive ( ar_namespace smallint NOT NULL default '0', ar_title varchar(255) NOT NULL default '', ar_text text NOT NULL default '', ar_comment varchar(255) NOT NULL default '', ar_user int NOT NULL default '0', ar_user_text varchar(255) NOT NULL, ar_timestamp char(14) NOT NULL default '', ar_minor_edit boolean NOT NULL default 'f', ar_flags varchar(255) NOT NULL default '' );

CREATE TABLE links ( l_from varchar(255) NOT NULL default '', l_to int NOT NULL default '0' );

CREATE TABLE brokenlinks ( bl_from int NOT NULL default '0', bl_to varchar(255) NOT NULL default '' );

CREATE TABLE imagelinks ( il_from varchar(255) NOT NULL default '', il_to varchar(255) NOT NULL default '' );

CREATE TABLE site_stats ( ss_row_id int NOT NULL PRIMARY KEY, ss_total_views bigint default '0', ss_total_edits bigint default '0', ss_good_articles bigint default '0' );

CREATE TABLE ipblocks ( ipb_address varchar(40) NOT NULL default '', ipb_user int NOT NULL default '0', ipb_by int NOT NULL default '0', ipb_reason varchar(255) NOT NULL default '', ipb_timestamp char(14) NOT NULL default '' );

CREATE TABLE image ( img_name varchar(255) NOT NULL default '', img_size int NOT NULL default '0', img_description varchar(255) NOT NULL default '', img_user int NOT NULL default '0', img_user_text varchar(255) NOT NULL default '', img_timestamp char(14) NOT NULL default '' );

CREATE TABLE oldimage ( oi_name varchar(255) NOT NULL default '', oi_archive_name varchar(255) NOT NULL default '', oi_size int NOT NULL default 0, oi_description varchar(255) NOT NULL default '', oi_user int NOT NULL default '0', oi_user_text varchar(255) NOT NULL default '', oi_timestamp char(14) NOT NULL default '' );

CREATE TABLE random ( ra_current smallint NOT NULL default 0, ra_title varchar(255) NOT NULL default '' );

CREATE TABLE recentchanges ( rc_timestamp varchar(14) NOT NULL default '', rc_cur_time varchar(14) NOT NULL default '', rc_user int NOT NULL default '0', rc_user_text varchar(255) NOT NULL default '', rc_namespace smallint NOT NULL default '0', rc_title varchar(255) NOT NULL default '', rc_comment varchar(255) NOT NULL default '', rc_minor boolean NOT NULL default 'f', rc_bot boolean NOT NULL default 'f', rc_new boolean NOT NULL default 'f', rc_cur_id int NOT NULL default '0', rc_this_oldid int NOT NULL default '0', rc_last_oldid int NOT NULL default '0' );

CREATE TABLE watchlist ( wl_user int NOT NULL, wl_namespace smallint NOT NULL default '0', wl_title varchar(255) NOT NULL default '' );

CREATE TABLE math ( math_inputhash char(16) NOT NULL PRIMARY KEY, math_outputhash char(16) NOT NULL, math_conservative bool NOT NULL, math_html text NOT NULL );

Of course, this isn't "real" code, and many changes will be necessary to make it any useful. Anyway: * user and old are reserved keywords in Postgres * why are we using tinyblob(1) instead of bool for boolean data ? * why are we creating so many indexes ? are all of them necessary ? * shouldn't we use database-provided timestamps instead of varchar(14) ? * rights and restrictions don't seem to be represented very efficiently. using integer flag for that seems like a better idea to me * it might be good idea to consider making our own searching system instead of relying on something provided by database