DELIMITER $$  
CREATE PROCEDURE `partition_create`(SCHEMANAME varchar(64), TABLENAME varchar(64), PARTITIONNAME varchar(64), CLOCK int)  
BEGIN  
    DECLARE RETROWS INT;  
    SELECT COUNT(1) INTO RETROWS  
    FROM information_schema.partitions  
    WHERE table_schema = SCHEMANAME AND   
    table_name = TABLENAME AND partition_description >= CLOCK;  
    IF RETROWS = 0 THEN  
        SELECT CONCAT( "partition_create(", SCHEMANAME, ",", TABLENAME, ",", PARTITIONNAME, ",", CLOCK, ")" ) AS msg;  
        SET @sql = CONCAT( 'ALTER TABLE ', SCHEMANAME, '.', TABLENAME, ' ADD PARTITION (PARTITION ', PARTITIONNAME, ' VALUES LESS THAN (', CLOCK, '));' );  
        PREPARE STMT FROM @sql;  
        EXECUTE STMT;  
        DEALLOCATE PREPARE STMT;  
    END IF;
END$$  
DELIMITER ;

DELIMITER $$
CREATE PROCEDURE `partition_drop`(SCHEMANAME VARCHAR(64), TABLENAME VARCHAR(64), DELETE_BELOW_PARTITION_DATE BIGINT)
BEGIN
    /*
        SCHEMANAME = The DB schema in which to make changes
        TABLENAME = The table with partitions to potentially delete
        DELETE_BELOW_PARTITION_DATE = Delete any partitions with names that are dates older than this one (yyyy-mm-dd)
    */
    DECLARE done INT DEFAULT FALSE;
    DECLARE drop_part_name VARCHAR(16);
    /*
        Get a list of all the partitions that are older than the date
        in DELETE_BELOW_PARTITION_DATE.  All partitions are prefixed with
        a "p", so use SUBSTRING TO get rid of that character.
    */
    DECLARE myCursor CURSOR FOR
        SELECT partition_name
        FROM information_schema.partitions
        WHERE table_schema = SCHEMANAME AND table_name = TABLENAME AND CAST(SUBSTRING(partition_name FROM 2) AS UNSIGNED) < DELETE_BELOW_PARTITION_DATE;
        DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
    /*
       Create the basics for when we need to drop the partition.  Also, create
       @drop_partitions to hold a comma-delimited list of all partitions that
       should be deleted.
    */
    SET @alter_header = CONCAT("ALTER TABLE ", SCHEMANAME, ".", TABLENAME, " DROP PARTITION ");
    SET @drop_partitions = "";
    /*
       Start looping through all the partitions that are too old.
    */
    OPEN myCursor;
    read_loop: LOOP
        FETCH myCursor INTO drop_part_name;
        IF done THEN
            LEAVE read_loop;
        END IF;
        SET @drop_partitions = IF(@drop_partitions = "", drop_part_name, CONCAT(@drop_partitions, ",", drop_part_name));
    END LOOP;
    IF @drop_partitions != "" THEN
        /*
           1. Build the SQL to drop all the necessary partitions.
           2. Run the SQL to drop the partitions.
           3. Print out the table partitions that were deleted.
        */
        SET @full_sql = CONCAT(@alter_header, @drop_partitions, ";");
        PREPARE STMT FROM @full_sql;
        EXECUTE STMT;
        DEALLOCATE PREPARE STMT;
        SELECT CONCAT(SCHEMANAME, ".", TABLENAME) AS `table`, @drop_partitions AS `partitions_deleted`;
    ELSE
        /*
           No partitions are being deleted, so print out "N/A" (Not applicable) to indicate
           that no changes were made.
        */
        SELECT CONCAT(SCHEMANAME, ".", TABLENAME) AS `table`, "N/A" AS `partitions_deleted`;
    END IF;
END$$
DELIMITER ;

DELIMITER $$
CREATE PROCEDURE `partition_maintenance`(SCHEMA_NAME VARCHAR(32), TABLE_NAME VARCHAR(32), KEEP_DATA_DAYS INT, HOURLY_INTERVAL INT, CREATE_NEXT_INTERVALS INT)
BEGIN
    DECLARE OLDER_THAN_PARTITION_DATE VARCHAR(16);
    DECLARE PARTITION_NAME VARCHAR(16);
    DECLARE OLD_PARTITION_NAME VARCHAR(16);
    DECLARE LESS_THAN_TIMESTAMP INT;
    DECLARE CUR_TIME INT;
    CALL partition_verify(SCHEMA_NAME, TABLE_NAME, HOURLY_INTERVAL);
    SET CUR_TIME = UNIX_TIMESTAMP(DATE_FORMAT(NOW(), '%Y-%m-%d 00:00:00'));
    SET @__interval = 1;
    create_loop: LOOP
        IF @__interval > CREATE_NEXT_INTERVALS THEN
            LEAVE create_loop;
        END IF;
        SET LESS_THAN_TIMESTAMP = CUR_TIME + (HOURLY_INTERVAL * @__interval * 3600);
        SET PARTITION_NAME = FROM_UNIXTIME(CUR_TIME + HOURLY_INTERVAL * (@__interval - 1) * 3600, 'p%Y%m%d%H00');
        IF(PARTITION_NAME != OLD_PARTITION_NAME) THEN
            CALL partition_create(SCHEMA_NAME, TABLE_NAME, PARTITION_NAME, LESS_THAN_TIMESTAMP);
        END IF;
        SET @__interval=@__interval+1;
        SET OLD_PARTITION_NAME = PARTITION_NAME;
    END LOOP;
    SET OLDER_THAN_PARTITION_DATE=DATE_FORMAT(DATE_SUB(NOW(), INTERVAL KEEP_DATA_DAYS DAY), '%Y%m%d0000');
    CALL partition_drop(SCHEMA_NAME, TABLE_NAME, OLDER_THAN_PARTITION_DATE);
END$$
DELIMITER ;

DELIMITER $$
CREATE PROCEDURE `partition_verify`(SCHEMANAME VARCHAR(64), TABLENAME VARCHAR(64), HOURLYINTERVAL INT(11))
BEGIN
    DECLARE PARTITION_NAME VARCHAR(16);
    DECLARE RETROWS INT(11);
    DECLARE FUTURE_TIMESTAMP TIMESTAMP;
    SELECT COUNT(1) INTO RETROWS
    FROM information_schema.partitions
    WHERE table_schema = SCHEMANAME AND table_name = TABLENAME AND partition_name IS NULL;
    IF RETROWS = 1 THEN
        SET FUTURE_TIMESTAMP = TIMESTAMPADD(HOUR, HOURLYINTERVAL, CONCAT(CURDATE(), " ", '00:00:00'));
        SET PARTITION_NAME = DATE_FORMAT(CURDATE(), 'p%Y%m%d%H00');
        SET @__PARTITION_SQL = CONCAT("ALTER TABLE ", SCHEMANAME, ".", TABLENAME, " PARTITION BY RANGE(`clock`)");
        SET @__PARTITION_SQL = CONCAT(@__PARTITION_SQL, "(PARTITION ", PARTITION_NAME, " VALUES LESS THAN (", UNIX_TIMESTAMP(FUTURE_TIMESTAMP), "));");
        PREPARE STMT FROM @__PARTITION_SQL;
        EXECUTE STMT;
        DEALLOCATE PREPARE STMT;
    END IF;
END$$
DELIMITER ;

DELIMITER $$
CREATE PROCEDURE `partition_maintenance_all`(SCHEMA_NAME VARCHAR(32))
BEGIN
    CALL partition_maintenance(SCHEMA_NAME, 'history', 35, 24, 14);
    CALL partition_maintenance(SCHEMA_NAME, 'history_log', 35, 24, 14);
    CALL partition_maintenance(SCHEMA_NAME, 'history_str', 35, 24, 14);
    CALL partition_maintenance(SCHEMA_NAME, 'history_text', 35, 24, 14);
    CALL partition_maintenance(SCHEMA_NAME, 'history_uint', 35, 24, 14);
    CALL partition_maintenance(SCHEMA_NAME, 'trends', 365, 24, 14);
    CALL partition_maintenance(SCHEMA_NAME, 'trends_uint', 365, 24, 14);
END$$
DELIMITER ;