diff options
| -rw-r--r-- | doc/src/sgml/xindex.sgml | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/doc/src/sgml/xindex.sgml b/doc/src/sgml/xindex.sgml index d3942be6a7f..b5f4a67f525 100644 --- a/doc/src/sgml/xindex.sgml +++ b/doc/src/sgml/xindex.sgml @@ -1,5 +1,5 @@ <!-- -$Header: /cvsroot/pgsql/doc/src/sgml/xindex.sgml,v 1.9 2000/03/28 02:53:02 tgl Exp $ +$Header: /cvsroot/pgsql/doc/src/sgml/xindex.sgml,v 1.10 2000/03/28 02:59:55 tgl Exp $ Postgres documentation --> @@ -107,7 +107,7 @@ SELECT oid FROM pg_am WHERE amname = 'btree'; impose a strict ordering on keys, lesser to greater. Since <productname>Postgres</productname> allows the user to define operators, <productname>Postgres</productname> cannot look at the name of an operator - (eg, ">" or "<") and tell what kind of comparison it is. In fact, + (eg, ">" or "<") and tell what kind of comparison it is. In fact, some access methods don't impose any ordering at all. For example, <acronym>R-tree</acronym>s express a rectangle-containment relationship, whereas a hashed data structure expresses only bitwise similarity based @@ -115,7 +115,7 @@ SELECT oid FROM pg_am WHERE amname = 'btree'; needs some consistent way of taking a qualification in your query, looking at the operator and then deciding if a usable index exists. This implies that <productname>Postgres</productname> needs to know, for - example, that the "<=" and ">" operators partition a + example, that the "<=" and ">" operators partition a <acronym>B-tree</acronym>. <productname>Postgres</productname> uses strategies to express these relationships between operators and the way they can be used to scan indices. @@ -203,7 +203,7 @@ SELECT oid FROM pg_am WHERE amname = 'btree'; <note> <para> Strictly speaking, this routine can return a negative - number (< 0), 0, or a non-zero positive number (> 0). + number (< 0), 0, or a non-zero positive number (> 0). </para> </note> </para> @@ -427,11 +427,11 @@ CREATE OPERATOR = ( FROM pg_am am, pg_opclass opcl, complex_ops_tmp c WHERE amname = 'btree' AND opcname = 'complex_abs_ops' AND - c.oprname = '<'; + c.oprname = '<'; </programlisting> Now do this for the other operators substituting for the "1" in the - third line above and the "<" in the last line. Note the order: + third line above and the "<" in the last line. Note the order: "less than" is 1, "less than or equal" is 2, "equal" is 3, "greater than or equal" is 4, and "greater than" is 5. </para> |