Speed up SUM() on a result with JOINS in MySQL
I have a query with a combination of 6 left joins and inner joins. The query gives a result of 25000 records in 112ms. When I do a SUM() the query takes 4s. A SUM() another table with 35000 records without joins take 100ms (without index) to execute. I am unable to understand why. I am using MySQL.
mysql join
asked May 29 '16 at 7:52
Jaseem AbbasJaseem Abbas
1183
bumped to the homepage by Community♦ 12 mins ago
This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
add a comment |
I have a query with a combination of 6 left joins and inner joins. The query gives a result of 25000 records in 112ms. When I do a SUM() the query takes 4s. A SUM() another table with 35000 records without joins take 100ms (without index) to execute. I am unable to understand why. I am using MySQL.
mysql join
asked May 29 '16 at 7:52
Jaseem AbbasJaseem Abbas
1183
bumped to the homepage by Community♦ 12 mins ago
This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
The speed of an operation depends on the size of the tables overall, the internal structure of the data, and how the data needs to be organised/parsed. You can't expect a direct relationship between the number of records on a table and the time it takes an operation to complete. You'll need to provide the DDL of your tables, your queries, and an explain/analyze results to get any specific support.
– Ziggy Crueltyfree Zeitgeister
May 30 '16 at 1:26
1
Use EXPLAIN to get the query plans with and without thesum(), compare them and if you don't see a solution, add them to your question.
– jkavalik
May 30 '16 at 8:55
add a comment |
I have a query with a combination of 6 left joins and inner joins. The query gives a result of 25000 records in 112ms. When I do a SUM() the query takes 4s. A SUM() another table with 35000 records without joins take 100ms (without index) to execute. I am unable to understand why. I am using MySQL.
mysql join
asked May 29 '16 at 7:52
Jaseem AbbasJaseem Abbas
1183
I have a query with a combination of 6 left joins and inner joins. The query gives a result of 25000 records in 112ms. When I do a SUM() the query takes 4s. A SUM() another table with 35000 records without joins take 100ms (without index) to execute. I am unable to understand why. I am using MySQL.
mysql join
mysql join
asked May 29 '16 at 7:52
Jaseem AbbasJaseem Abbas
1183
asked May 29 '16 at 7:52
Jaseem AbbasJaseem Abbas
1183
asked May 29 '16 at 7:52
Jaseem AbbasJaseem Abbas
1183
asked May 29 '16 at 7:52
Jaseem AbbasJaseem Abbas
1183
asked May 29 '16 at 7:52
Jaseem AbbasJaseem Abbas
1183
1183
bumped to the homepage by Community♦ 12 mins ago
This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
bumped to the homepage by Community♦ 12 mins ago
This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
The speed of an operation depends on the size of the tables overall, the internal structure of the data, and how the data needs to be organised/parsed. You can't expect a direct relationship between the number of records on a table and the time it takes an operation to complete. You'll need to provide the DDL of your tables, your queries, and an explain/analyze results to get any specific support.
– Ziggy Crueltyfree Zeitgeister
May 30 '16 at 1:26
1
Use EXPLAIN to get the query plans with and without thesum(), compare them and if you don't see a solution, add them to your question.
– jkavalik
May 30 '16 at 8:55
add a comment |
The speed of an operation depends on the size of the tables overall, the internal structure of the data, and how the data needs to be organised/parsed. You can't expect a direct relationship between the number of records on a table and the time it takes an operation to complete. You'll need to provide the DDL of your tables, your queries, and an explain/analyze results to get any specific support.
– Ziggy Crueltyfree Zeitgeister
May 30 '16 at 1:26
1
Use EXPLAIN to get the query plans with and without thesum(), compare them and if you don't see a solution, add them to your question.
– jkavalik
May 30 '16 at 8:55
The speed of an operation depends on the size of the tables overall, the internal structure of the data, and how the data needs to be organised/parsed. You can't expect a direct relationship between the number of records on a table and the time it takes an operation to complete. You'll need to provide the DDL of your tables, your queries, and an explain/analyze results to get any specific support.
– Ziggy Crueltyfree Zeitgeister
May 30 '16 at 1:26
The speed of an operation depends on the size of the tables overall, the internal structure of the data, and how the data needs to be organised/parsed. You can't expect a direct relationship between the number of records on a table and the time it takes an operation to complete. You'll need to provide the DDL of your tables, your queries, and an explain/analyze results to get any specific support.
– Ziggy Crueltyfree Zeitgeister
May 30 '16 at 1:26
1
1
Use EXPLAIN to get the query plans with and without the
sum(), compare them and if you don't see a solution, add them to your question.– jkavalik
May 30 '16 at 8:55
Use EXPLAIN to get the query plans with and without the
sum(), compare them and if you don't see a solution, add them to your question.– jkavalik
May 30 '16 at 8:55
add a comment |
1 Answer
1
active
oldest
votes
SELECT SUM(...)
FROM ...
JOIN ...
usually computes an inflated value for SUM. This is because the JOIN inflates the number of rows over which SUM applies.
See if you can write something like
SELECT ( SELECT SUM(...) FROM ... WHERE ... ) -- a correlated subquery
FROM
...
If you want more discussion, show us your code.
answered Jun 6 '16 at 4:57
Rick JamesRick James
42k22258
add a comment |
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1 Answer
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1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
SELECT SUM(...)
FROM ...
JOIN ...
usually computes an inflated value for SUM. This is because the JOIN inflates the number of rows over which SUM applies.
See if you can write something like
SELECT ( SELECT SUM(...) FROM ... WHERE ... ) -- a correlated subquery
FROM
...
If you want more discussion, show us your code.
answered Jun 6 '16 at 4:57
Rick JamesRick James
42k22258
add a comment |
SELECT SUM(...)
FROM ...
JOIN ...
usually computes an inflated value for SUM. This is because the JOIN inflates the number of rows over which SUM applies.
See if you can write something like
SELECT ( SELECT SUM(...) FROM ... WHERE ... ) -- a correlated subquery
FROM
...
If you want more discussion, show us your code.
answered Jun 6 '16 at 4:57
Rick JamesRick James
42k22258
add a comment |
SELECT SUM(...)
FROM ...
JOIN ...
usually computes an inflated value for SUM. This is because the JOIN inflates the number of rows over which SUM applies.
See if you can write something like
SELECT ( SELECT SUM(...) FROM ... WHERE ... ) -- a correlated subquery
FROM
...
If you want more discussion, show us your code.
answered Jun 6 '16 at 4:57
Rick JamesRick James
42k22258
SELECT SUM(...)
FROM ...
JOIN ...
usually computes an inflated value for SUM. This is because the JOIN inflates the number of rows over which SUM applies.
See if you can write something like
SELECT ( SELECT SUM(...) FROM ... WHERE ... ) -- a correlated subquery
FROM
...
If you want more discussion, show us your code.
answered Jun 6 '16 at 4:57
Rick JamesRick James
42k22258
answered Jun 6 '16 at 4:57
Rick JamesRick James
42k22258
answered Jun 6 '16 at 4:57
Rick JamesRick James
42k22258
answered Jun 6 '16 at 4:57
Rick JamesRick James
42k22258
42k22258
add a comment |
add a comment |
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The speed of an operation depends on the size of the tables overall, the internal structure of the data, and how the data needs to be organised/parsed. You can't expect a direct relationship between the number of records on a table and the time it takes an operation to complete. You'll need to provide the DDL of your tables, your queries, and an explain/analyze results to get any specific support.
– Ziggy Crueltyfree Zeitgeister
May 30 '16 at 1:26
1
Use EXPLAIN to get the query plans with and without the
sum(), compare them and if you don't see a solution, add them to your question.– jkavalik
May 30 '16 at 8:55