Release Notes

|22.21 Working with Large Query Results

|It is easy for a user to produce a query that returns a large number of |rows. It is not so easy for a user to predict how many rows might |actually be returned. With a query that could potentially return |thousands (or millions) of rows, there are two problems: |

1. |It can take a long time to retrieve the result.
2. |A large amount of client memory can be required to hold the result. |

|To facilitate this process, DB2 breaks up large result sets into |chunks. It will retrieve and display the results of a query one chunk |at a time.

|As a result: |

1. |Display time will be reduced as the first chunk of a query is available |for viewing while the remaining chunks are being retrieved.
2. |Memory requirements on the client will be reduced as only one chunk of a |query result will be stored on the client at any given time. |

|To control the number of query result rows in |memory:: |

1. |Open the General page of the Tool Settings notebook.
2. |In the Maximum size section, select: |
   • |Sample Contents to limit the number of result rows displayed in |the Sample Contents window. Specify the chunk size of the result set |(number of rows) in the entry field.
   • |Command Center to limit the number of result rows displayed on |the Query Results page of the Command Center. Specify the chunk size of |the result set (number of rows) in the entry field. |
   |

|When working with the results of a query in the Sample Contents window or |on the Query Results page of the Command Center, the Rows in memory |field indicates the number of rows being held in memory for the query. |This number will never be greater than the Maximum size set. |Click on Next to retrieve to the next chunk of the result |set. When Next is inactive, you have reached the end of the |result set.