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4
votes
1answer
55 views

PL/pgSQL issues when function used twice (caching problem ?)

I am facing an absolutely weird problem that feels much like a Postgres bug than an algorithm problem. I have this function: CREATE FUNCTION sp_connect(mail character varying, passwd character ...
3
votes
0answers
52 views

Is execution plan cached “better” for stored procedures than for a non-dynamic query?

Reading different explanations about execution plan caching by Microsoft SQL Server, I'm confused about the benefits of using stored procedures instead of non-dynamic queries. By a non-dynamic query ...
2
votes
1answer
36 views

Questions about DBCC FREEPROCCACHE

I used spAskBrent for troubleshooting a SQL Server 2005 performance issue. I found the problem was someone had ran DBCC FREEPROCCACHE. It caused low performance (very low PLE) on my database and ...
1
vote
0answers
29 views

Reasons why plans of sys.dm_exec_cached_plans do not match actual plans?

I re-assess index / query optimization and actually focus on key/bookmark lookpus that could be eliminated. Using a script of Jonathan Kehayas I go through the list of query plans that used those ...
0
votes
0answers
65 views

how to minimize the effect of updating statistics on the plan cache?

The issue I am trying to address: After updating statistics there are slow downs in running many of our processes here. then following the scary dba on this link below: ...
5
votes
1answer
437 views

A possible infinite recompile was detected for SQLHANDLE

I have been finding strange error messages on the sql error log: Bocss: same deadlock taking place every hour – needs investigating Also lots of recompiles are listed in the error log for other ...
1
vote
0answers
26 views

AlwaysOn AG Live Migration

A couple of thoughts on AlwaysOn AG migrations: Is there a reason why Microsoft didn't implement similar technology to Hyper-V Live Migration to AlwaysOn AGs so that the buffer pool and cache are ...
1
vote
1answer
45 views

Plans created several times under Force Parameterization

People use forced parameterization to save plan compilation cost. However, I found things different here. The query I will run is as following, and under AdventureWorks2012 database: DECLARE @Var ...
9
votes
1answer
274 views

Would it be better for query plans to be split by statement for re-usability?

From my limited knowledge of how query plans are compiled, stored and retrieved by queries I understand that a multi statement query or stored procedure will generate it's query plan which will be ...
2
votes
1answer
444 views

Monitoring the Postgres query parser

As I understand it, when you send a query to Postgres like: SELECT id FROM table1 WHERE name = $1; Postgres will create a query plan. The plan will be cached for the same query in the same ...
1
vote
0answers
124 views

Different Execution Plans Picked for Similar Queries

Thank you in advance for reading it. This question is kind of long and need a little patience to read. I will provide as much details as I can to void interference factors to solve this problem. ...
1
vote
0answers
57 views

Flush procedure cache or drop and create?

Okay I had a very strange issue today on SQL Server 2005. We had a stored procedure update that added new parameters to part of it. One database out of ~150 or more seem to not work properly. Using ...
7
votes
1answer
1k views

Query plan cache bloated by ad-hoc queries, even with “Optimize for Ad-hoc Workloads”

I've been noticing what I thought to be unusual issues with our query plan cache, where the plans in the cache were never more than a day old. Through running the following query (courtesy of ...
3
votes
2answers
1k views

View scripts ran by a specific user?

I read in a stackoverflow post that you can restore scripts from the past 24 hours by using this query: Use <database> SELECT execquery.last_execution_time AS [Date Time], execsql.text AS ...
2
votes
0answers
177 views

plan_generation_num keeps incrementing, why?

I have a query that is executed using sp_executesql code is as follows DECLARE @rsk NVARCHAR(1) = '1', @ppCityID NVARCHAR(3); SET @ppCityID = CAST(@cityID AS NVARCHAR(3)); exec sp_executesql ...
2
votes
1answer
115 views

Will cleaning data cache help to resolve compiler memory pressure?

I currently experience RESOURCE_SEMAPHORE_QUERY_COMPILE waits causing CPU spike 100% that lasts 10-20 mins and disappears only by completely stopping traffic. I figured it could be a memory pressure ...
2
votes
2answers
379 views

Stored procedure compilation blocking due to many parameters to sp_executesql

I am seeing blocking due to locks on compiling a particular stored procedure (as described in KB 263889). Basically, several processes are waiting with LCK_M_X on the same resource "TAB: ...