mirrors/postgres
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Remove time travel from manuals.

Browse Source
This commit is contained in:
Bruce Momjian 1997-11-03 04:47:08 +00:00
parent 475a8873b0
commit 7589967613
1 changed files with 7 additions and 48 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

55
src/man/sql.l
View File

@ -1,6 +1,6 @@
.\" This is -*-nroff-*-
.\" XXX standard disclaimer belongs here....
.\" $Header: /cvsroot/pgsql/src/man/Attic/sql.l,v 1.6 1997/10/01 18:53:29 momjian Exp $
.\" $Header: /cvsroot/pgsql/src/man/Attic/sql.l,v 1.7 1997/11/03 04:47:08 momjian Exp $
.TH INTRODUCTION SQL 11/5/95 PostgreSQL PostgreSQL
.SH "Section 4 \(em SQL Commands (COMMANDS)"
.SH "General Information"
@ -132,8 +132,6 @@ A
is either an attribute of a given class or one of the following:
.nf
oid
tmin
tmax
xmin
xmax
cmin
@ -145,19 +143,16 @@ stands for the unique identifier of an instance which is added by
Postgres to all instances automatically. Oids are not reused and are 32
bit quantities.
.PP
.IR "Tmin, tmax, xmin, cmin, xmax"
.IR "Xmin, cmin, xmax"
and
.IR cmax
stand respectively for the time that the instance was inserted, the
time the instance was deleted, the identity of the inserting
stand respectively for the identity of the inserting
transaction, the command identifier within the transaction, the
identity of the deleting transaction and its associated deleting
command. For further information on these fields consult [STON87].
Times are represented internally as instances of the \*(lqabstime\*(rq
data type. Transaction identifiers are 32 bit quantities which are
assigned sequentially starting at 512. Command identifiers are 16 bit
objects; hence, it is an error to have more than 65535 SQL commands
within one transaction.
data type. Transaction and command identifiers are 32 bit quantities.
Transactions are assigned sequentially starting at 512.
.SH "Columns"
A
.IR column
@ -301,53 +296,17 @@ where
.IR class_reference
is of the form
.nf
class_name [time_expression] [*]
class_name [*]
.fi
The
.IR "from expression"
defines one or more instance variables to range over the class
indicated in
.IR class_reference .
Adding a
.IR time_expression
will indicate that a historical class is desired. One can also request
One can also request
the instance variable to range over all classes that are beneath the
indicated class in the inheritance hierarchy by postpending the
designator \*(lq*\*(rq.
.SH‚‚ "Time Expressions"
A
.IR "time expression"
is in one of two forms:
.nf
["date"]
["date-1", "date-2"]
.fi
The first case requires instances that are valid at the indicated
time. The second case requires instances that are valid at some time
within the date range specified. If no time expression is indicated,
the default is \*(lqnow\*(rq.
.PP
In each case, the date is a character string of the form
.nf
"[MON-FRI] MMM DD [HH:MM:SS] YYYY [Timezone]"
.fi
where MMM is the month (Jan \- Dec), DD is a legal day number in the
specified month, HH:MM:SS is an optional time in that day (24-hour
clock), and YYYY is the year. If the time of day HH:MM:SS is not
specified, it defaults to midnight at the start of the specified day.
As of Version 3.0, times are no longer read and written using
Greenwich Mean Time; the input and output routines default to the
local time zone.
.PP
For example,
.nf
["Jan 1 1990"]
["Mar 3 00:00:00 1980", "Mar 3 23:59:59 1981"]
.fi
are valid time specifications.
.PP
Note that this syntax is slightly different than that used by the
time-range type.
.SH "SEE ALSO"
insert(l),
delete(l),