Which might affect the write performance when inserting into the table. It is deliberately simple with no indexes or foreign key references This post should highlight the importance of using bulk inserts and what may be surprising, even if you areįamiliar with bulk inserts, is just how much better a multi-row insert can be even when dealing with a smallīefore I get into the performance comparison, let's look at some example SQL of the two approaches. It copies data to and from files but I'm not going to cover it in Is great for loading large volumes of data. This way we can build up a single SQL statementįor many rows and send it altogether to the database to be executed.Īs an aside, Postgres also supports a COPY command which Into the table, to the VALUES clause of the INSERT command. It can be done by supplying multiple sets of values, each representing a row to be inserted In this post I will compare the performance of a multi-row insert, aĬommon way of bulk inserting data, in Postgres with a simple iterative insert which sends one SQL statement per row.Ī multi-row insert is a database feature which allows you to insert multiple rows into a table with a single Of the benefits of using bulk insert techniques to write data to the database instead of iteratively writingĭata as lots of individual statements. Most people who have experience with relational databases such as SQL Server, Postgres, and MySQL will be aware Note that, the returning clause is an extension to the INSERT statement provided by PostgreSQL over the SQL standard.Image credit: Ian Taylor on Unsplash Databases Postgres Performance: Multi-Row Insert In this tutorial, we learned how to insert single or multiple records into the table along with the RETURNING clause. RETURNING * Code language: PostgreSQL SQL dialect and PL/pgSQL ( pgsql ) Returning All Column ValuesĪs you can see, using the * symbol will return all column values for all records. INSERT INTO employees ( name, department, salary, hire_date) However, if you want to see all column values, use the asterisk (*) sign as shown below. Returning Column ValuesĪs you can see, all the values are printed. Here, we are returning the values of all columns. RETURNING id, name, department, salary, hire_date Code language: PostgreSQL SQL dialect and PL/pgSQL ( pgsql ) Let’s now see an example of the RETURNING clause. RETURNING col2 as ID Code language: PostgreSQL SQL dialect and PL/pgSQL ( pgsql ) Examples of the RETURNING Clause You can also use the alias for the returning column value using the following syntax- INSERT INTO table(col2,col3) VALUES If you want to return the whole row, you can use the * symbol after the RETURNING keyword. Here, the query will return the values of col2 after completing the insertion operation. RETURNING col2 Code language: PostgreSQL SQL dialect and PL/pgSQL ( pgsql ) You can return the inserted row names, ids or entire rows. The INSERT statement also provides us with the optional clause RETURNING which returns the information about the inserted row/rows. RETURNING Clause in PostgreSQL INSERT Statement ( 'Sarah Lee', 'Finance', 65000.00, '') Code language: PostgreSQL SQL dialect and PL/pgSQL ( pgsql ) Insert Multiple RecordsĪs you can see, now we got 0 3, which means three records have been inserted into the table. If you are a beginner and remember these things, you are good to go! In case of multiple rows, each row must be separated by a comma too. comma separated values: Every value must be separated from each other by a comma.
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