Executing sql queries, Cancelling a query from the sql whiteboard, Statement details pane – HP Integrity NonStop J-Series User Manual
Page 102
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When a statement is executed and the number of rows in the result set exceeds the Rows/Page
threshold, statement execution happens in the page mode. Partial results are retrieved and
displayed.
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When statement execution happens in the page mode, the Statement Details pane displays
Next Page. The following considerations apply:
◦
Until you click Next Page, the execution is paused, and the SQL cursor remains open.
However, the Time Elapsed timer continues to run because it tracks the wait time.
◦
When you click Next Page, the next page of results is retrieved from the server. The first
page is deleted from the grid when the new page is loaded. The process repeats until
you either view all the pages or cancel the query.
◦
You cannot return to the previous page because the ODBC cursor operates in the
FORWARD mode only. To display earlier results, you must re-execute the statement.
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Regardless of whether the number of rows in the result set exceeds the Rows/Page threshold,
if the available virtual memory falls below the internal threshold, the statement execution goes
into the page mode and displays the results that have been retrieved so far. In this case, the
grid might display fewer rows than the Rows/Page threshold. This situation continues until
garbage collection begins, and the memory occupied by the pages that have been disposed
becomes available again. When the system resources are low, the Statement Details pane
displays a message that execution is in the entering page mode.
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Grid sorting works only on the currently displayed page.
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In the page mode, the following options copy data for the current page only:
Data to Clipboard
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Data to Browser
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Data to Spreadsheet
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Data to File
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To free workstation memory, you can discard the results of the selected statement(s) cached
in the Statement List pane. For more information, see
“Statement List pane” (page 99)
.
Executing SQL queries
If you highlight text, you can execute a part of a statement.
If you highlight text in the Statement pane, and click Execute, the query formed by that text is
executed. For example, if the Statement pane contains the query,
select * from t
, where t1
= 1, and if you highlight the part
select * from t
and click Execute,
select * from t
is
executed.
Cancelling a query from the SQL Whiteboard
You can cancel a running query if the query is wrong, the query is inefficient, or if the query is
creating a performance issue and needs to be stopped.
After a query starts executing, the SQL Whiteboard Execute button changes to Cancel. Clicking
Cancel terminates the SQL query.
Statement Details pane
The Statement Details pane contains statistics and details generated from the selected statement
in the Statement List pane. You can use these details for reference only. The pane has no interactive
functionality. Statistics appear only for statements that are loaded from the Statement pane.
describes the fields that appear in the Execution Results tab when a statement
executes successfully.
102 Using the SQL Whiteboard