A SQL statement typically used to `UPDATE` records when they exist and `INSERT` them when they do not.

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oracle merge operation hangs (or loops); query tuner claims it's a cartesian product operation

I have a Merge query (open to better suggestions) that seems to cause the server to hang. (I'm not sure what it's doing, but it pegs the CPU and never completes) When I run it through the query ...
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0answers
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Once in a while synchronization of the independently updated mysql databases problem

I have a production database and a test database running on MySQL with MyISAM and InnoDB tables, which are updated independently. The Production database is updated by system and sometimes by a user. ...
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3answers
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SQL Server 2008 merge statement deadlocking itself

I have the following procedure (SQL Server 2008r2): create procedure usp_SaveCompanyUserData @companyId bigint, @userId bigint, @dataTable tt_CoUserdata readonly as begin set ...
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2answers
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Merge replication fails on executing query

My merge replication was working fine this morning. Since an hour or 2 ago, my synchronisation status windows keeps showing this message: Thread id 3108 will wait for 15 second(s) before retrying the ...
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2answers
566 views

How to use merge hints to isolate complex queries in SQL Server

I can understand that if I join individual queries that are "individually fast" the combination may become slow because the default execution plan may be non-optimal. However when I know the number ...
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1answer
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What are my locking options for a Merge statement?

I have a stored procedure that performs a MERGE statement. It seems like it locks the whole table by default when performing the merge. I'm calling this stored procedure inside of a transaction ...
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0answers
197 views

What overhead is there if I MERGE row by row?

I have a target table of about 2000 rows and I want to be able to MERGE (with HOLDLOCK) about 5-10 rows at a time into the target table. The target table doesn't get used heavily, with only 1-2 users ...
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1answer
133 views

Re-subscribing to a merge publication after edits made offline

Hypothetical Question - To help scenario planning. Let's say I have a 2008 R2 Merge Publication with 5 active subscribers. The publication is deleted and all subscriptions are removed. A week or so ...
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Oracle's Merge v. Select->Update/Insert

What is the faster statement? A MERGE or Select->Update/Insert depending on if it returns a value? I'm trying to optimize a database, but I haven't found any speed tests comparing the two. I found ...