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Favourite performance tuning tricks [closed]
...n-optimal query plan
Break up the Join
Can you break up the join?
Pre-select foreign keys into a temporary table
Do half the join and put results in a temporary table
Are you using the right kind of temporary table?
#temp tables may perform much better than @table variables with large volum...
Errors: “INSERT EXEC statement cannot be nested.” and “Cannot use the ROLLBACK statement within an I
...our stored procedure data into it
EXAMPLE:
INSERT INTO #YOUR_TEMP_TABLE
SELECT * FROM OPENROWSET ('SQLOLEDB','Server=(local);TRUSTED_CONNECTION=YES;','set fmtonly off EXEC [ServerName].dbo.[StoredProcedureName] 1,2,3')
Note: You MUST use 'set fmtonly off', AND you CANNOT add dynamic sql to this...
How to allocate aligned memory only using the standard library?
...better idea, please say so...
[Added:
The 'standard' trick is to create a union of 'likely to be maximally aligned types' to determine the requisite alignment. The maximally aligned types are likely to be (in C99) 'long long', 'long double', 'void *', or 'void (*)(void)'; if you include <stdint...
How to return result of a SELECT inside a function in PostgreSQL?
... bigint
, ratio bigint) AS
$func$
BEGIN
RETURN QUERY
SELECT t.txt
, count(*) AS cnt -- column alias only visible inside
, (count(*) * 100) / _max_tokens -- I added brackets
FROM (
SELECT t.txt
FROM token t
WHERE t.charty...
Correct format specifier to print pointer or address?
...e representation and alignment requirements as each other. All pointers to union types shall have the same representation and alignment requirements as each other. Pointers to other types need not have the same representation or alignment requirements.
39) The same representation and alignment ...
Equals(=) vs. LIKE
... can produce results different from the = comparison operator:
mysql> SELECT 'ä' LIKE 'ae' COLLATE latin1_german2_ci;
+-----------------------------------------+
| 'ä' LIKE 'ae' COLLATE latin1_german2_ci |
+-----------------------------------------+
| 0 |...
Why should we typedef a struct so often in C?
...ep C Secrets". The gist is: You WANT to know that something is a struct or union, not HIDE it.
– Jens
Mar 14 '12 at 10:31
34
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Can git be integrated with Xcode?
...indow. Since your working directory is set to the parent directory of the selected file the command is nice and short.
I have no connection at all with Decimus. I am just a satisfied user who has run thousands of commands through DTerm.
Edit: As of 27 August 2009 DTerm is free. If you bought your...
What is the PostgreSQL equivalent for ISNULL()
...
SELECT CASE WHEN field IS NULL THEN 'Empty' ELSE field END AS field_alias
Or more idiomatic:
SELECT coalesce(field, 'Empty') AS field_alias
share...
How to create a MySQL hierarchical recursive query
... or self-joins.
MySQL 8+
with recursive cte (id, name, parent_id) as (
select id,
name,
parent_id
from products
where parent_id = 19
union all
select p.id,
p.name,
p.parent_id
from products p
inner join cte
...