From bb1095c66d48b492236993ce793371e3236d051e Mon Sep 17 00:00:00 2001 From: Bruce Momjian Date: Thu, 15 Feb 2001 22:15:10 +0000 Subject: [PATCH] Update FAQ. --- doc/FAQ | 57 +++++++++++---------------------------- doc/src/FAQ/FAQ.html | 64 +++++++++++--------------------------------- 2 files changed, 32 insertions(+), 89 deletions(-) diff --git a/doc/FAQ b/doc/FAQ index 7057213a70..083c3938cc 100644 --- a/doc/FAQ +++ b/doc/FAQ @@ -83,25 +83,21 @@ other users? 4.17) What is an OID? What is a TID? 4.18) What is the meaning of some of the terms used in PostgreSQL? - 4.19) Why do I get the error "FATAL: palloc failure: memory - exhausted?" - 4.20) How do I tell what PostgreSQL version I am running? - 4.21) My large-object operations get invalid large obj descriptor. + 4.19) How do I tell what PostgreSQL version I am running? + 4.20) My large-object operations get invalid large obj descriptor. Why? - 4.22) How do I create a column that will default to the current time? - 4.23) Why are my subqueries using IN so slow? - 4.24) How do I perform an outer join? + 4.21) How do I create a column that will default to the current time? + 4.22) Why are my subqueries using IN so slow? + 4.23) How do I perform an outer join? Extending PostgreSQL 5.1) I wrote a user-defined function. When I run it in psql, why does it dump core? - 5.2) What does the message "NOTICE:PortalHeapMemoryFree: 0x402251d0 - not in alloc set!" mean? - 5.3) How can I contribute some nifty new types and functions to + 5.2) How can I contribute some nifty new types and functions to PostgreSQL? - 5.4) How do I write a C function to return a tuple? - 5.5) I have changed a source file. Why does the recompile not see the + 5.3) How do I write a C function to return a tuple? + 5.4) I have changed a source file. Why does the recompile not see the change? _________________________________________________________________ @@ -887,26 +883,11 @@ BYTEA bytea variable-length byte array (null-safe) A list of general database terms can be found at: http://www.comptechnews.com/~reaster/dbdesign.html - 4.19) Why do I get the error "FATAL: palloc failure: memory exhausted?" - - It is possible you have run out of virtual memory on your system, or - your kernel has a low limit for certain resources. Try this before - starting the postmaster: - ulimit -d 65536 - limit datasize 64m - - Depending on your shell, only one of these may succeed, but it will - set your process data segment limit much higher and perhaps allow the - query to complete. This command applies to the current process, and - all subprocesses created after the command is run. If you are having a - problem with the SQL client because the backend is returning too much - data, try it before starting the client. - - 4.20) How do I tell what PostgreSQL version I am running? + 4.19) How do I tell what PostgreSQL version I am running? From psql, type select version(); - 4.21) My large-object operations get invalid large obj descriptor. Why? + 4.20) My large-object operations get invalid large obj descriptor. Why? You need to put BEGIN WORK and COMMIT around any use of a large object handle, that is, surrounding lo_open ... lo_close. @@ -920,12 +901,12 @@ BYTEA bytea variable-length byte array (null-safe) If you are using a client interface like ODBC you may need to set auto-commit off. - 4.22) How do I create a column that will default to the current time? + 4.21) How do I create a column that will default to the current time? Use now(): CREATE TABLE test (x int, modtime timestamp DEFAULT now() ); - 4.23) Why are my subqueries using IN so slow? + 4.22) Why are my subqueries using IN so slow? Currently, we join subqueries to outer queries by sequentially scanning the result of the subquery for each row of the outer query. A @@ -941,7 +922,7 @@ SELECT * We hope to fix this limitation in a future release. - 4.24) How do I perform an outer join? + 4.23) How do I perform an outer join? PostgreSQL 7.1 and later supports outer joins using the SQL standard syntax. Here are two examples: @@ -980,23 +961,17 @@ SELECT * The problem could be a number of things. Try testing your user-defined function in a stand-alone test program first. - 5.2) What does the message "NOTICE:PortalHeapMemoryFree: 0x402251d0 not in - alloc set!" mean? - - You are pfree'ing something that was not palloc'ed. Beware of mixing - malloc/free and palloc/pfree. - - 5.3) How can I contribute some nifty new types and functions to PostgreSQL? + 5.2) How can I contribute some nifty new types and functions to PostgreSQL? Send your extensions to the pgsql-hackers mailing list, and they will eventually end up in the contrib/ subdirectory. - 5.4) How do I write a C function to return a tuple? + 5.3) How do I write a C function to return a tuple? This requires wizardry so extreme that the authors have never tried it, though in principle it can be done. - 5.5) I have changed a source file. Why does the recompile not see the + 5.4) I have changed a source file. Why does the recompile not see the change? The Makefiles do not have the proper dependencies for include files. diff --git a/doc/src/FAQ/FAQ.html b/doc/src/FAQ/FAQ.html index 4324be49e4..59ad51047f 100644 --- a/doc/src/FAQ/FAQ.html +++ b/doc/src/FAQ/FAQ.html @@ -127,17 +127,15 @@ TID?
4.18) What is the meaning of some of the terms used in PostgreSQL?
- 4.19) Why do I get the error "FATAL: palloc - failure: memory exhausted?"
- 4.20) How do I tell what PostgreSQL version I + 4.19) How do I tell what PostgreSQL version I am running?
- 4.21) My large-object operations get + 4.20) My large-object operations get invalid large obj descriptor. Why?
- 4.22) How do I create a column that will + 4.21) How do I create a column that will default to the current time?
- 4.23) Why are my subqueries using + 4.22) Why are my subqueries using IN so slow?
- 4.24) How do I perform an outer join?
+ 4.23) How do I perform an outer join?
@@ -145,14 +143,11 @@
5.1) I wrote a user-defined function. When I run it in psql, why does it dump core?
- 5.2) What does the message - "NOTICE:PortalHeapMemoryFree: 0x402251d0 not in alloc set!" - mean?
- 5.3) How can I contribute some nifty new types + 5.2) How can I contribute some nifty new types and functions to PostgreSQL?
- 5.4) How do I write a C function to return a + 5.3) How do I write a C function to return a tuple?
- 5.5) I have changed a source file. Why does the + 5.4) I have changed a source file. Why does the recompile not see the change?
@@ -1137,32 +1132,13 @@ BYTEA bytea variable-length byte array (null-safe)

A list of general database terms can be found at: http://www.comptechnews.com/~reaster/dbdesign.html

-

4.19) Why do I get the error "FATAL: - palloc failure: memory exhausted?"
-

- -

It is possible you have run out of virtual memory on your - system, or your kernel has a low limit for certain resources. Try - this before starting the postmaster:

-
-    ulimit -d 65536
-    limit datasize 64m
-
- Depending on your shell, only one of these may succeed, but it will - set your process data segment limit much higher and perhaps allow - the query to complete. This command applies to the current process, - and all subprocesses created after the command is run. If you are - having a problem with the SQL client because the - backend is returning too much data, try it before starting the - client. - -

4.20) How do I tell what PostgreSQL version +

4.19) How do I tell what PostgreSQL version I am running?

From psql, type select version();

-

4.21) My large-object operations get +

4.20) My large-object operations get invalid large obj descriptor. Why?

@@ -1179,7 +1155,7 @@ BYTEA bytea variable-length byte array (null-safe)

If you are using a client interface like ODBC you may need to set auto-commit off.

-

4.22) How do I create a column that will +

4.21) How do I create a column that will default to the current time?

@@ -1189,7 +1165,7 @@ BYTEA bytea variable-length byte array (null-safe) -

4.23) Why are my subqueries using +

4.22) Why are my subqueries using IN so slow?

@@ -1212,7 +1188,7 @@ BYTEA bytea variable-length byte array (null-safe) We hope to fix this limitation in a future release. -

4.24) How do I perform an outer join?
+

4.23) How do I perform an outer join?

PostgreSQL 7.1 and later supports outer joins using the SQL @@ -1264,28 +1240,20 @@ BYTEA bytea variable-length byte array (null-safe)

The problem could be a number of things. Try testing your user-defined function in a stand-alone test program first.

-

5.2) What does the message - "NOTICE:PortalHeapMemoryFree: 0x402251d0 not in alloc set!" - mean?

- -

You are pfree'ing something that was not - palloc'ed. Beware of mixing malloc/free and - palloc/pfree.

- -

5.3) How can I contribute some nifty new +

5.2) How can I contribute some nifty new types and functions to PostgreSQL?

Send your extensions to the pgsql-hackers mailing list, and they will eventually end up in the contrib/ subdirectory.

-

5.4) How do I write a C function to return a +

5.3) How do I write a C function to return a tuple?

This requires wizardry so extreme that the authors have never tried it, though in principle it can be done.

-

5.5) I have changed a source file. Why does +

5.4) I have changed a source file. Why does the recompile not see the change?

The Makefiles do not have the proper dependencies for -- 2.40.0