From 106d0ba7a2cd4bda3c75204d4cb1a1ffdcc810ce Mon Sep 17 00:00:00 2001 From: mo khan Date: Fri, 31 Jan 2020 13:21:24 -0700 Subject: fix typo --- doc/unit-4.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/doc/unit-4.md b/doc/unit-4.md index 2a159ac..b5bd1ba 100644 --- a/doc/unit-4.md +++ b/doc/unit-4.md @@ -331,7 +331,7 @@ Guidelines: 6. Indexes on large values is not optimal. Try to find a smaller coded value to index to represent the larger value. 7. If the key for the index is used to determine the location where the record will be stored then a surrogate key should be used. 8. Check DBMS for limits on the # of indexes on a table. (limits include # of indexes, and size of index) -9. Be careful indexes attributes that have null values. some systems don't index `null` so sequential scan is needed for `null` value. +9. Be careful of indexing attributes that have null values. some systems don't index `null` so sequential scan is needed for `null` value. ### Designing a database for optimal query performance -- cgit v1.2.3