Merge pull request svozniuk#9 from rahulsaini/patch-1

svozniuk · web-flow · commit fc501573ca1b · 2017-04-06T19:23:57.000+02:00
Update Database (Oracle).txt
diff --git a/Databases/Database (Oracle).txt b/Databases/Database (Oracle).txt
@@ -261,13 +261,15 @@ Are database Indexes useful? What is the role of them?
   well as data volumes increase.
 
 Why many indexes are not good for performance
-todo
+Too many indexes will result in more frequent INDEX REBUILD operations which are costly to the database table.
+If a table has many indexes and is read heavy and has very less writes (UPDATE / INSERT) instead of SELECT then Indexes will actually speed up the query.
+However if there are too many indexes and table has frequent writes then costly Index Rebuild operations will be very frequent.
 
 What does it mean database de-normalization?
 todo
 
-Which of SELECT, UPDATE, DELETE, ADD�s performance is mostly affected by performance of indexes?
+Which of SELECT, UPDATE, DELETE, ADDs performance is mostly affected by performance of indexes?
 todo
 
 What are ways to increase performance of database
-todo
+todo
