Update index stats sybase

Sarosh Siddiqui. Robin Rocky. Georshemill Morales. Jorge Guillermo Schmidt. Raghavendra Prabhu. Francisco Delafuente Catalan Heineken. Richa Pandey. More From Prasanna Kirtani. Prasanna Kirtani. Popular in Database Index. Siva Bhai. Lauro Bath. Reddy sekhar. Akxar V. Mohammed Hussain. Raluca Hodorogea. Bujji John. Mohd Fauzi. Harjinder SIngh. Constantin Alexandru Florea. Carlos Alberto Chong Antonio. Note that only local indexes of the partition are considered.

Global indexes are not considered. Also note that updating the statistics for a partition also updates the global statistics i. So this update statistics does have a high impact on the performance of the server and requires more space in tempdb.

Also note that in many cases statistics are mostly useful for columns referenced by indexes especially as leading columns.

Updating statistics for other columns create an overhead. But in some cases it is required and better than using update all statistics. The former creates histograms not only for the leading column of the index but for all columns specified in the index definition.

You can also update the statistics for all columns of all indexes on the table by omitting the index name:. Note that it is not exactly the same as calling update index statistics for each index on the table since the latter updates the statistics of columns referenced by multiple indexes multiple times.

This is basically the same problem as when using update statistics on columns which are not the leading column of an index. Each table is analyzed c. Adds optimized search arguments and join clauses d.

The query is prased and normalized 2 Which of the following is not true about this query? The query optimizer will consider performing a table scan.

The query optimizer will consider using the index on salesman c. The query optimizer will choose an access method based on cost 3 The optimizer considers the size of the table in determining which aspects of a query Plan? Choose 3 a. Serial Scan versus Parallel Scan b. Inner table versus Outer Table c. Index selection versus table scan d. Partition based versus hash based scan 4 Given the following query: Select T.

Which of the following indexes will the ASE optimizer consider using? Create index idx1 on titles price d. Adaptive server will give an error and the trigger will not fire. Adaptive server will give and error but the trigger will be fired.

By default creating an index on an empty table generates statistics on its leading column c. Dropping an index does not delete any column statistics By default creating an index on a table with data generates statistics on its leading column.

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