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SET_SESSION_AUTHORIZATION.7
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'\" t .\" Title: SET SESSION AUTHORIZATION .\" Author: The PostgreSQL Global Development Group .\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/> .\" Date: 2017-11-06 .\" Manual: PostgreSQL 9.2.24 Documentation .\" Source: PostgreSQL 9.2.24 .\" Language: English .\" .TH "SET SESSION AUTHORIZATION" "7" "2017-11-06" "PostgreSQL 9.2.24" "PostgreSQL 9.2.24 Documentation" .\" ----------------------------------------------------------------- .\" * Define some portability stuff .\" ----------------------------------------------------------------- .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .\" http://bugs.debian.org/507673 .\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" ----------------------------------------------------------------- .\" * set default formatting .\" ----------------------------------------------------------------- .\" disable hyphenation .nh .\" disable justification (adjust text to left margin only) .ad l .\" ----------------------------------------------------------------- .\" * MAIN CONTENT STARTS HERE * .\" ----------------------------------------------------------------- .SH "NAME" SET_SESSION_AUTHORIZATION \- set the session user identifier and the current user identifier of the current session .\" SET SESSION AUTHORIZATION .SH "SYNOPSIS" .sp .nf SET [ SESSION | LOCAL ] SESSION AUTHORIZATION \fIuser_name\fR SET [ SESSION | LOCAL ] SESSION AUTHORIZATION DEFAULT RESET SESSION AUTHORIZATION .fi .SH "DESCRIPTION" .PP This command sets the session user identifier and the current user identifier of the current SQL session to be \fIuser_name\fR\&. The user name can be written as either an identifier or a string literal\&. Using this command, it is possible, for example, to temporarily become an unprivileged user and later switch back to being a superuser\&. .PP The session user identifier is initially set to be the (possibly authenticated) user name provided by the client\&. The current user identifier is normally equal to the session user identifier, but might change temporarily in the context of SECURITY DEFINER functions and similar mechanisms; it can also be changed by SET ROLE (\fBSET_ROLE\fR(7))\&. The current user identifier is relevant for permission checking\&. .PP The session user identifier can be changed only if the initial session user (the authenticated user) had the superuser privilege\&. Otherwise, the command is accepted only if it specifies the authenticated user name\&. .PP The SESSION and LOCAL modifiers act the same as for the regular \fBSET\fR(7) command\&. .PP The DEFAULT and RESET forms reset the session and current user identifiers to be the originally authenticated user name\&. These forms can be executed by any user\&. .SH "NOTES" .PP \fBSET SESSION AUTHORIZATION\fR cannot be used within a SECURITY DEFINER function\&. .SH "EXAMPLES" .sp .if n \{\ .RS 4 .\} .nf SELECT SESSION_USER, CURRENT_USER; session_user | current_user \-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\- peter | peter SET SESSION AUTHORIZATION \*(Aqpaul\*(Aq; SELECT SESSION_USER, CURRENT_USER; session_user | current_user \-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\- paul | paul .fi .if n \{\ .RE .\} .SH "COMPATIBILITY" .PP The SQL standard allows some other expressions to appear in place of the literal \fIuser_name\fR, but these options are not important in practice\&. PostgreSQL allows identifier syntax ("username"), which SQL does not\&. SQL does not allow this command during a transaction; PostgreSQL does not make this restriction because there is no reason to\&. The SESSION and LOCAL modifiers are a PostgreSQL extension, as is the RESET syntax\&. .PP The privileges necessary to execute this command are left implementation\-defined by the standard\&. .SH "SEE ALSO" SET ROLE (\fBSET_ROLE\fR(7))