MySql Query takes forever

mysql

hi I am doing A query to get some product info, but there is something strange going on, the first query returns resultset fast (.1272s) but the second (note that I just added 1 column) takes forever to complete (28-35s), anyone know what is happening?

query 1

SELECT
p.partnumberp,
p.model,
p.descriptionsmall,
p.brandname,
sum(remainderint) stockint
from
inventario_dbo.inventoryindetails ind
left join purchaseorders.product p on (p.partnumberp = ind.partnumberp)
left join inventario_dbo.inventoryin ins on (ins.inventoryinid= ind.inventoryinid)
group by partnumberp, projectid

query 2

SELECT
p.partnumberp,
p.model,
p.descriptionsmall,
p.brandname,
p.descriptiondetail,
sum(remainderint) stockint
from
inventario_dbo.inventoryindetails inda
left join purchaseorders.product p on (p.partnumberp = inda.partnumberp)
left join inventario_dbo.inventoryin ins on (ins.inventoryinid= inda.inventoryinid)
group by partnumberp, projectid

Best Solution

Is descriptiondetail a really large column? Sounds like it could be a lot of text compared to the other fields based on its name, so maybe it just takes a lot more time to read from disk, but if you could post the schema detail for the purchaseorders.product table or maybe the average length of that column that would help.

Otherswise I would try running the query a few times and see you consistently get the same time results. Could just be load on the database server the time you got the slower result.

Related Solutions

Mysql – concatenate multiple MySQL rows into one field

You can use GROUP_CONCAT:

SELECT person_id,
   GROUP_CONCAT(hobbies SEPARATOR ', ')
FROM peoples_hobbies
GROUP BY person_id;

As Ludwig stated in his comment, you can add the DISTINCT operator to avoid duplicates:

SELECT person_id,
   GROUP_CONCAT(DISTINCT hobbies SEPARATOR ', ')
FROM peoples_hobbies
GROUP BY person_id;

As Jan stated in their comment, you can also sort the values before imploding it using ORDER BY:

SELECT person_id, 
       GROUP_CONCAT(hobbies ORDER BY hobbies ASC SEPARATOR ', ')
FROM peoples_hobbies
GROUP BY person_id;

As Dag stated in his comment, there is a 1024 byte limit on the result. To solve this, run this query before your query:

SET group_concat_max_len = 2048;

Of course, you can change 2048 according to your needs. To calculate and assign the value:

SET group_concat_max_len = CAST(
                     (SELECT SUM(LENGTH(hobbies)) + COUNT(*) * LENGTH(', ')
                           FROM peoples_hobbies
                           GROUP BY person_id) AS UNSIGNED);

Mysql – Which MySQL data type to use for storing boolean values

For MySQL 5.0.3 and higher, you can use BIT. The manual says:

As of MySQL 5.0.3, the BIT data type is used to store bit-field values. A type of BIT(M) enables storage of M-bit values. M can range from 1 to 64.

Otherwise, according to the MySQL manual you can use BOOL or BOOLEAN, which are at the moment aliases of tinyint(1):

Bool, Boolean: These types are synonyms for TINYINT(1). A value of zero is considered false. Non-zero values are considered true.

MySQL also states that:

We intend to implement full boolean type handling, in accordance with standard SQL, in a future MySQL release.

References: http://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.html