Temporary tables ​

A temporary table belongs to one logical connection and lives in its temp namespace. It is useful for staging data or reusing intermediate rows within that connection.

Syntax ​

CREATE TEMP TABLE name (column type, ...)
CREATE TEMPORARY TABLE name (column type, ...)

A temporary table shadows a table of the same unqualified name in main. Qualify the source as main.name or temp.name when both exist.

A native client connection retains its temporary tables. HTTP requests use separate sessions, so create and use a temporary table in the same HTTP request.

Example ​

Main and temporary tables with the same name ​

CREATE TABLE staging(id UInt8);
INSERT INTO main.staging VALUES (1);
CREATE TEMP TABLE staging(id UInt8);
INSERT INTO temp.staging VALUES (7);

SELECT id FROM staging
FORMAT csv;

7

SELECT id FROM main.staging
FORMAT csv;

1

DROP TABLE temp.staging removes the temporary table explicitly. Its rows are not a persistent staging area across connections.