How do you recompile a query?

To recompile a stored procedure by using sp_recompile Select New Query, then copy and paste the following example into the query window and click Execute. This does not execute the procedure but it does mark the procedure to be recompiled so that its query plan is updated the next time that the procedure is executed.

What is query hint?

Query hints specify that the indicated hints are used in the scope of a query. They affect all operators in the statement. If UNION is involved in the main query, only the last query involving a UNION operation can have the OPTION clause. Query hints are specified as part of the OPTION clause.

How option recompile is invoked?

When executing a stored procedure with a WITH RECOMPILE option in the EXECUTE statement, a new query execution plan is created and used for this specific execution, but it’s not stored in cache. If there is already a plan in cache for this specific stored procedure, it’s intact.

Which is better inline query or stored procedure?

every query is submited it will be compiled & then executed. where as stored procedure is compiled when it is submitted for the first time & this compiled content is stored in something called procedure cache,for subsequent calls no compilation,just execution & hence better performance than query.

What is hint in Oracle with example?

Hints provide a mechanism to instruct the optimizer to choose a certain query execution plan based on the specific criteria. For example, you might know that a certain index is more selective for certain queries. Based on this information, you might be able to choose a more efficient execution plan than the optimizer.

How do you use parallel hint in update statement?

The PARALLEL hint (placed immediately after the UPDATE or DELETE keyword) applies not only to the underlying scan operation, but also to the UPDATE or DELETE operation. Alternatively, you can specify UPDATE or DELETE parallelism in the PARALLEL clause specified in the definition of the table to be modified.

How do you give a hint in Oracle?

Use the INDEX hint for function-based, domain, B-tree, bitmap, and bitmap join indexes. When working with tables containing ST_Geometry attributes and a st_spatial_index, specify the Oracle INDEX hint and the name of the st_spatial_index to instruct the optimizer to access the data by way of the index.

Should I use option recompile?

Use of OPTION(RECOMPILE) generally will lead to optimal plan choice and will provide different (and generally correct) cardinality estimation at every query execution, base every time on the value(s) of parameteres provided.

What’s the difference between recompile query hint and with recompil query hint?

This allows only that query (not all) in the stored procedure to recompile. WITH RECOMPILE option recompiles the whole stored procedure which might not be needed/beneficial if the stored procedure has many queries and only some of them need to be recompiled.

When to use recompile hint in stored procedure?

Say we have a stored procedure that has two queries in it – the second query uses a recompile hint, and you might recognize it from my parameter sniffing session: The first query will always get the same plan, but the second query will get different plans and return different numbers of rows depending on which reputation we pass in.

What happens when a recompile is used in a query?

The first query’s plan stuck around in memory, so it now shows 2 executions, and 2 total rows returned. Its row metrics are correct through the life of the stored procedure’s time in cache. However, the second query – the one with the recompile hint – has a brand new plan in the cache, but also new metrics.

Do you get row metrics with recompile hint?

Its row metrics are correct through the life of the stored procedure’s time in cache. However, the second query – the one with the recompile hint – has a brand new plan in the cache, but also new metrics. You’re not just recompiling the execution plan, but you’re also not getting query plan metrics here.