diff --git a/doc/FAQ b/doc/FAQ
index d7e2d5ea596..e1c3cf1999a 100644
--- a/doc/FAQ
+++ b/doc/FAQ
@@ -1,7 +1,7 @@
Frequently Asked Questions (FAQ) for PostgreSQL
- Last updated: Fri Jul 29 10:05:09 EDT 2005
+ Last updated: Wed Aug 10 15:29:42 EDT 2005
Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us)
@@ -79,6 +79,7 @@
4.19) Why do I get "relation with OID ##### does not exist" errors
when accessing temporary tables in PL/PgSQL functions?
4.20) What replication solutions are available?
+ 4.21) Why are my table and column names not recognized in my query?
_________________________________________________________________
General Questions
@@ -471,6 +472,12 @@
The maximum table size and maximum number of columns can be quadrupled
by increasing the default block size to 32k.
+ One limitation is that indexes can not be created on columns longer
+ than about 2,000 characters. Fortunately, such indexes are rarely
+ needed. Uniqueness is best guaranteed using another column that is an
+ MD5 hash of the long column, and full text indexing allows for
+ searching of words within the column.
+
4.5) How much database disk space is required to store data from a typical
text file?
@@ -578,6 +585,11 @@
expresssion index, it will be used:
CREATE INDEX tabindex ON tab (lower(col));
+ If the above index is created as UNIQUE, though the column can store
+ upper and lowercase characters, it can not have identical values that
+ differ only in case. To force a particular case to be stored in the
+ column, use a CHECK constraint or a trigger.
+
4.9) In a query, how do I detect if a field is NULL? How can I sort on
whether a field is NULL or not?
@@ -776,3 +788,16 @@
There are also commercial and hardware-based replication solutions
available supporting a variety of replication models.
+
+ 4.20) Why are my table and column names not recognized in my query?
+
+ The most common cause is the use of double-quotes around table or
+ column names during table creation. When double-quotes are used, table
+ and column names (called identifiers) are stored case-sensitive,
+ meaning you must use double-quotes when referencing the names in a
+ query. Some interfaces, like pgAdmin, automatically double-quote
+ identifiers during table creation. So, for identifiers to be
+ recognized, you must either:
+ * Avoid double-quoting identifiers when creating tables
+ * Use only lowercase characters in identifiers
+ * Double-quote identifiers when referencing them in queries
diff --git a/doc/src/FAQ/FAQ.html b/doc/src/FAQ/FAQ.html
index 71e659db94d..07dd956e2ef 100644
--- a/doc/src/FAQ/FAQ.html
+++ b/doc/src/FAQ/FAQ.html
@@ -10,7 +10,7 @@
alink="#0000ff">
Frequently Asked Questions (FAQ) for PostgreSQL
- Last updated: Mon May 30 09:11:03 EDT 2005
+ Last updated: Wed Aug 10 15:29:42 EDT 2005
Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us)
@@ -26,7 +26,7 @@
General Questions
- 1.1) What is PostgreSQL? How is it pronounced?
+ 1.1) What is PostgreSQL? How is it pronounced?
1.2) What is the copyright of PostgreSQL?
1.3) What platforms does PostgreSQL support?
1.4) Where can I get PostgreSQL?
@@ -116,7 +116,9 @@
does not exist" errors when accessing temporary tables in PL/PgSQL
functions?
4.20) What replication solutions are available?
-
+ 4.21) Why are my table and column names not
+ recognized in my query?
+
@@ -124,8 +126,10 @@
1.1) What is PostgreSQL? How is it pronounced?
- PostgreSQL is pronounced Post-Gres-Q-L, also called just
- Postgres.
+ PostgreSQL is pronounced Post-Gres-Q-L, and is also sometimes
+ referred to as just Postgres. An audio file is available in
+ MP3 format for
+ those would like to hear the pronunciation.
PostgreSQL is an object-relational database system that has the
features of traditional commercial database systems with
@@ -613,6 +617,12 @@ table?
unlimited |
The maximum table size and maximum number of columns can be
quadrupled by increasing the default block size to 32k.
+ One limitation is that indexes can not be created on columns
+ longer than about 2,000 characters. Fortunately, such indexes are
+ rarely needed. Uniqueness is best guaranteed using another column
+ that is an MD5 hash of the long column, and full text indexing
+ allows for searching of words within the column.
+
4.5) How much database disk space is required
to store data from a typical text file?
@@ -740,7 +750,12 @@ table?unlimited |
CREATE INDEX tabindex ON tab (lower(col));
-
+ If the above index is created as UNIQUE, though
+ the column can store upper and lowercase characters, it can not have
+ identical values that differ only in case. To force a particular
+ case to be stored in the column, use a CHECK
+ constraint or a trigger.
+
4.9) In a query, how do I detect if a field
is NULL? How can I sort on whether a field is
NULL or not?
@@ -1000,5 +1015,22 @@ length
There are also commercial and hardware-based replication solutions
available supporting a variety of replication models.
+
+ 4.20) Why are my table and column names not
+ recognized in my query?
+
+ The most common cause is the use of double-quotes around table or
+ column names during table creation. When double-quotes are used,
+ table and column names (called identifiers) are stored case-sensitive, meaning you must use
+ double-quotes when referencing the names in a query. Some interfaces,
+ like pgAdmin, automatically double-quote identifiers during table
+ creation. So, for identifiers to be recognized, you must either:
+
+ - Avoid double-quoting identifiers when creating tables
+ - Use only lowercase characters in identifiers
+ - Double-quote identifiers when referencing them in queries
+