Cursors can be either updateable or non-updateable. If you only need to display information and not diddle with it, the non-updateable is the fastest. The provider simply passes you the data and forgets about it! There is no need to keep tabs on the data to see if it has… Continue reading
char[(n)] – Fixed-length non-Unicode character data with length of n bytes. n must be a value from 1 through 8,000. Storage size is n bytes. The SQL-92 synonym for char is character. nvarchar(n) – Variable-length Unicode character data of n characters. n must be a value from 1 through 4,000…. Continue reading
Text and image. Use text for character data if you need to store more than 255 characters in SQL Server 6.5, or more than 8000 in SQL Server 7.0. Use image for binary large objects (BLOBs) such as digital images. With text and image data types, the data is not… Continue reading
Temporary setting of specific server characteristics is done by trace tags. DBCC TRACEON is the command to set the trace flags. Once activated, trace flag will be in effect until the server is restarted. Trace frags are frequently used for diagnosing performance issues. For example, the trace flag 3205 is… Continue reading
The following is the process to make a remote connection in database: Use SQL Server Surface Area Configuration Tool for enabling the remote connection in database. Click on Surface Area Configuration for Services and Connections. Click on SQLEXPRESS/Database Engine/RemoteConnections Select the radio button: Local and Remote Connections and select ‘Using… Continue reading
A segment is a part of relational data base and consists of one or more extents. Each extent is further divided into blocks. Every segment has an index for holding all of its data for quick data retrieval. Index segments can be created explicitly by using the CREATE INDEX command…. Continue reading
Cross Join: No join conditions are specified. Results in pairs of rows. Results in Cartesian product of two tables. Full Outer Join: A combination of both left and right outer joins. Results in every row from both of the tables , at least once. Assigns NULL for unmatched fields.
A differential backup is a type of data backup that preserves data, saving only the difference in the data since the last full backup. The rationale in this is that, since changes to data are generally few compared to the entire amount of data in the data repository, the amount… Continue reading
Merge replication is a feature offered by Microsoft SQL Servers that allows changes to be sent from one primary server, called a publisher, to one or more secondary servers, called subscribers. Merge replication is one of the modes available in the Microsoft SQL Server for distributing data to various servers… Continue reading
A Cartesian product is the result of an unrestricted join of two or more tables. The result set of a three table Cartesian product will have x * y * z number of rows where x, y, z correspond to the number of rows in each table involved in the… Continue reading