Search results
Results From The WOW.Com Content Network
Reserved words in SQL and related products In SQL:2023 [3] In IBM Db2 13 [4] In Mimer SQL 11.0 [5] In MySQL 8.0 [6] In Oracle Database 23c [7] In PostgreSQL 16 [1] In Microsoft SQL Server 2022 [2]
SQL-92 was the third revision of the SQL database query language. Unlike SQL-89, it was a major revision of the standard. Aside from a few minor incompatibilities, the SQL-89 standard is forward-compatible with SQL-92. The standard specification itself grew about five times compared to SQL-89.
In SQL, the TRUNCATE TABLE statement is a data manipulation language (DML) [1] operation that deletes all rows of a table without causing a triggered action. The result of this operation quickly removes all data from a table , typically bypassing a number of integrity enforcing mechanisms.
A database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes and storage space to maintain the index data structure. Indexes are used to quickly locate data without having to search every row in a database table every time said table is accessed.
When the time is expressed in the HH:MM:SS notation, the Roman ante/post-meridiem indicators (AM and PM) are also used frequently. In addition, they sometimes follow the convention of writing the Korean-style indicator before the time; it is not uncommon to encounter times expressed in such a way, e.g., “ AM 9:18 ” instead of “ 9:18 AM ”.
In addition, aliasing is required when doing self joins (i.e. joining a table with itself.) In SQL, you can alias tables and columns. A table alias is called a correlation name, according to the SQL standard. [1] A programmer can use an alias to temporarily assign another name to a table or column for the duration of the current SELECT query ...
In computer science, an inverted index (also referred to as a postings list, postings file, or inverted file) is a database index storing a mapping from content, such as words or numbers, to its locations in a table, or in a document or a set of documents (named in contrast to a forward index, which maps from documents to content). [1]
In database management systems, a reverse key index strategy reverses the key value before entering it in the index. [1] E.g., the value 24538 becomes 83542 in the index. Reversing the key value is particularly useful for indexing data such as sequence numbers , where each new key value is greater than the prior value, i.e., values ...