This allows a query's ORDER BY specification to be honored without a separate sorting step. DESC: Fetch data in descending order by using order by and limit clause in PostgreSQL. Limit is used to limit the number of records return … Ok I have a table with a indexed key and a non indexed field. I would like to … Indexes and ORDER BY. Syntax. Learn more . By default, B-tree indexes store their entries in ascending order with nulls last. This clause is an optional clause for select statement. Active 1 month ago. For example: SELECT last_name, first_name FROM contacts WHERE state = 'California' ORDER BY last_name; Viewed 913 times 1. Following is the syntax of the … How LIMIT clause works in PostgreSQL? As the query set returned by the SELECT statement has no specific order, one can use the ORDER BY clause in the SELECT statement to sort the results in the desired manner. This is done to eliminate redundancy in the output and/or compute aggregates that apply to these groups. Ask Question Asked 2 years, 6 months ago. When this attribute is omitted from the ORDER BY clause, the sort order is defaulted to ASC or ascending order. Active 2 years, 6 months ago. Python PostgreSQL - Order By. Usually if you try to retrieve data from a table, you will get the records in the same order in which you have inserted them. But I received ten random numbers sorted numerically: random ----- 0.102324520237744 0.17704638838768 0.533014383167028 0.60182224214077 … I need to find all records with a certain value and return the row. Ask Question Asked 9 years ago.

In addition to simply finding the rows to be returned by a query, an index may be able to deliver them in a specific sorted order.

Dear sirs, I was very surprised when I executed such SQL query (under PostgreSQL 8.2): select random() from generate_series(1, 10) order by random(); I thought I would receive ten random numbers in random order.

Next Page . sql ORDER BY multiple values in specific order? Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. We can use the limit clause by using the offset clause. Limit clause is very important in PostgreSQL. Of the index types currently supported by PostgreSQL, only B-tree can produce sorted output — the other index types return matching rows in an unspecified, … Of the index types currently supported by PostgreSQL, ... An important special case is ORDER BY in combination with LIMIT n: an explicit sort will have to process all the data to identify the first n rows, but if there is an index matching the ORDER BY then the first n rows can be retrieved directly, without scanning the remainder at all. Using the ORDER BY clause, while retrieving the records of a table you can sort the resultant records in ascending or descending order based on the desired column. The PostgreSQL ORDER BY clause can be used without specifying the ASC or DESC modifier.