What is Rowset positioning?
A rowset-positioned cursor is a cursor that can return one or more rows for a single fetch operation. The cursor is positioned on the set of rows that are to be fetched.
What is Multi row Fetch in DB2?
DB2. Multi row fetch is one of the most powerful features of DB2 V8, which can give significant performance improvements to of your DB2 application. So what is multi row fetch or MRF , as the name suggests it simply mean fetching multiple rows at a time using your cursor.
What does open cursor do in DB2?
OPEN DB2 cursor OPEN is an executable statement. It reads the SQL search fields, executes the SQL statement, and it builds the results table. This table is placed in Virtual Storage. It does not assign values to host variables, though.
What is scrollable cursor?
A scrollable cursor is cursor that can be moved in both a forward and a backward direction. Scrollable cursors can be either row-positioned or rowset-positioned.
What is the use of Sqlerrd 3?
For SQLCODES -911 and -913, SQLERRD(3) contains the reason code for the timeout or deadlock. When an error is encountered in parsing a dynamic statement, or when parsing, binding, or executing a native SQL procedure, SQLERRD(3) will contain the line number where the error was encountered.
What are the isolation levels in Db2?
In Db2 you can specify the following four isolation levels:
- cursor stability (CS),
- repeatable read (RR),
- read stability (RS), and.
- uncommitted read (UR).
What is cursor in Cobol Db2?
Db2 has a mechanism called a cursor . Using a cursor is like keeping your finger on a particular line of text on a printed page. In Db2, an application program uses a cursor to point to one or more rows in a set of rows that are retrieved from a table.
When would you use a cursor?
Use of Cursor The major function of a cursor is to retrieve data, one row at a time, from a result set, unlike the SQL commands which operate on all the rows in the result set at one time. Cursors are used when the user needs to update records in a singleton fashion or in a row by row manner, in a database table.
What is the difference between scrollable and non scrollable?
The difference between scrollable and non scrollable cursors in DB2 is that scrollable cursors are used to move randomly through the result set while non-scrollable cursors are used to move sequentially forward through the result set.
What are scrollable cursors and how useful are these?
What is Sqlstate?
SQLSTATE is a code which identifies SQL error conditions. It composed by five characters, which can be numbers or uppercase ASCII letters. An SQLSTATE value consists of a class (first two characters) and a subclass (last three characters).
How does row set positioning work in DB2?
ROWSET POSITIONING refers to how data is fetched from the database engine. For remote access, if any row qualifies, at least 1 row is returned as a rowset. The size of the rowset depends on the number of rows specified on the FETCH statement and on the number of rows that qualify. Data might be blocked and returned to the client in blocks.
Which is the best example of rowset positioning?
5 different best examples of Rowset positioning usage in DB2. These examples include to DELETE, UPDATE and SELECT multiple rows. Example SQL queries to use rowset positioning to carry INSERT, UPDATE and DELETE of Multi rows END-EXEC. The below query update salary to 5000 in all the rows of rowset result table. WHERE CURRENT OF C1 END-EXEC.
Can a cursor be used in a rowset statement?
Specifies that the cursor can be used with either row-positioned or rowset-positioned FETCH statements. This cursor can be used to return either a single row or multiple rows, as a rowset, with a single FETCH statement.
What is the definition of a rowset in SQL?
ROWSET POSITIONING refers to how data is fetched from the database engine. For remote access, if any row qualifies, at least 1 row is returned as a rowset. The size of the rowset depends on the number of rows specified on the FETCH statement and on the number of rows that qualify.
