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- SQL Server Integrity Violations
- We will discuss several of the most known reasons for errors and how to fix them step by step.
- The following might be some reasons for these violations:
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SQL Server Integrity Violations
If you are working on an application that uses SQL Server as its back end, it is important to be aware of the most common causes of integrity violations in order to avoid them.
We will discuss several of the most known reasons for errors and how to fix them step by step.
The FULLTEXT indexes are probably one of the very few things that can make your SQL Server crash without any external input. They are fragile, incomplete, and deprecated features from Microsoft’s Knowledge Base but they are still used today due to their expressive power. However, if you use them make sure not to include NULL values in your search clause because even though they do not match themselves, they produce UNKNOWN results which have a special meaning for FULLTEXT indexes.
Full-Text Search in SQL Server lets clients and applications run full-text inquiries against character-based information in SQL Server tables. Full-Text Index assists with performing complex questions against character information. Before we can run full-text questions on a table, first we really want to make a full-text record on the table.
Likewise, just one full-text record can be made on each table so in the event that you have an overabundance to be listed the sections must be moved to isolate tables. It is likewise critical to take note that full-text records are not refreshed immediately similar to the case with ordinary lists. Populating full-text files can be asset escalated so there are more choices that let you control when they are refreshed.
While customary grouped and non-bunched lists enable us to file most section datatypes they tragically are not upheld for any of the enormous article (LOB) data types. Full-text files can anyway be made on LOB datatype sections like TEXT, VARCHAR(MAX), IMAGE, VARBINARY(MAX) (it can likewise file CHAR and VARCHAR segment types). Without this usefulness, any question that referred to a section characterized with a LOB datatype would require a full output.
These are the main causes of integrity violations in SQL Server when using FULLTEXT indexes:
The index with the name ‘My Index’ already exists on the table ‘My Table’. This may happen if you use CREATE INDEX… ON … to create an index with a name identical to one that was previously created by the same user. Make sure to choose unique names when creating indexes or make sure that your application does not allow this kind of duplication.
The full-text catalog ‘FT Catalog’ is unavailable because it has not been upgraded since it was created. You will get this error if you try to create a new FULLTEXT index while there still exist unprocessed messages in the full-text catalog. You must be aware of the full-text logging process and make sure to empty the catalog before creating new indexes.
As opposed to FULLTEXT, FORCE_TEXT indexes are very reliable features that were first introduced in SQL Server 2005 as a replacement for text columns with a limited length – up to 900 bytes – that became an obstacle when working with documents longer than that limit. In order to fix integrity violations on these types of indexes, you have to consider two possibilities:
You attempted an operation that is not valid on a table with a clustered index defined. In all likelihood, this error message will pop up when you try to create a text index without specifying the table’s primary key in the definition clause. The solution is always to add the necessary clauses so that the index can rely on some kind of order being imposed on your data by means of one or more columns.
SQL Server provides us with a very intuitive way to monitor the respective performance of indexes on every table in our database whenever we need it. If an index is missing or has certain problems, SQL Server will notify us of the fact through integrity violations that pop up at inconvenient times.
The following might be some reasons for these violations:
Missing Index –
The CREATE INDEX statement that you issued against your table does not specify any key column(s) but your data still contains rows that are unique by means of one or more columns. This may happen if you have a primary key defined without declaring it as such and therefore, being invisible to those statements that rely on this declaration as a prerequisite. In order to avoid this error, make sure that there is an index defined for each unique key in your table.
Missing Non-clustered Index –
The definition clause of the index you attempted to create is missing either or both of its ORDERED and NONCLUSTERED attributes. This will happen if you have not specified a clustered index on your table and try to create an orderable non clustered one which cannot be useful on its own unless it exists together with another orderable non clustered index on the same table (in this case, there must be one such an index on every partition of such a clustered index). In such cases, make sure that you specify both of these attributes whenever you need them.
Invalid Unique/Primary Key Columns –
You tried to create a unique clustered index for your table and the number of key columns in its definition is greater than or equal to the number of rows it contains. In such cases, you must delete at least one column from this definition so that there can exist only as many key columns as rows in your table.
Invalid Index –
You tried to add an invalid index that specifies a data type that does not belong to any text, text, or image column; includes duplicate columns; or refers to a varchar(max), varchar(max), and varbinary(max) column with string length greater than 8,000 bytes (not considering user-defined and system delimiters).
Whenever you get integrity violations on indexes, make sure that you use the information provided by SQL Server in order to find out which ones are invalid or incorrectly defined. You can also make use of its ability to suggest solutions whenever it is possible for you to fix these problems by specifying their respective clauses through the drop index and altering index commands respectively.
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