Cursors allow row-by-row processing of the result-sets.
Types of cursors: Static, Dynamic, Forward-only, Keyset-driven.
Types of cursors: Static, Dynamic, Forward-only, Keyset-driven. See books online for more information.
Disadvantages of cursors: Each time you fetch a row from the cursor, it results in a network roundtrip, where as a normal SELECT query makes only one roundtrip, however large the resultset is. Cursors are also costly because they require more resources and temporary storage (results in more IO operations). Furthere, there are restrictions on the SELECT statements that can be used with some types of cursors.
04 February 2011
Diff in dropping a table || truncating a table || deleting all records
Dropping : (Table structure + Data are deleted), Invalidates the dependent objects ,Drops the indexes
Truncating: (Data alone deleted), Performs an automatic commit, Faster than delete
Delete : (Data alone deleted), Doesn’t perform automatic commit
Truncating: (Data alone deleted), Performs an automatic commit, Faster than delete
Delete : (Data alone deleted), Doesn’t perform automatic commit
Coders: UNIQUE constraints Vs UNIQUE index
Coders: UNIQUE constraints Vs UNIQUE index: "UNIQUE constraints Vs UNIQUE index"
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