create_shard_table.sql

delimiter //
drop table if exists shard_seq_tbl //
create table shard_seq_tbl ( nextval bigint not null primary key auto_increment ) engine = MyISAM //
alter table shard_seq_tbl AUTO_INCREMENT = 10000 //

drop function if exists shard_nextval //
create function shard_nextval()
returns bigint
begin
   insert into shard_seq_tbl values (NULL) ;
   set @R_ObjectId_val=LAST_INSERT_ID() ;
   delete from shard_seq_tbl ;
   return @R_ObjectId_val ;
end//

drop function if exists now_msec//
CREATE FUNCTION now_msec RETURNS STRING SONAME "now_msec.so"//

drop function if exists next_sharded_id //
CREATE function next_sharded_id ()
RETURNS bigint
 BEGIN
    DECLARE our_epoch bigint DEFAULT 1325419260000;
    DECLARE seq_id bigint;
    DECLARE now_millis bigint;
    DECLARE shard_id int DEFAULT 0;
    DECLARE result bigint UNSIGNED;

    SELECT MOD(shard_nextval(),1024) INTO seq_id;

    SELECT now_msec() INTO now_millis;
    set result := (now_millis - our_epoch) << 23;
    set result := result | (shard_id << 10);
    set result := result | (seq_id);
    RETURN result;
 END//
delimiter ;