I have to work with a database to do reporting The DB is quite big : 416 055 104 rows Each row is very light though, just booleans and int ids. Each row is identify by 3 columns, but at my surprise, there is no Primary Key on it. Only a Clustered Index with a unique constraint. So Knowing that, I have 2 question. Could there be ANY g...
How does Sql Server handle fill factor on tables with clustered indexes on composite primary keys? I would assume a key node value would be generated based on the fields that make up the clustered index. Would this mean that each new row inserted would effectively get inserted to at the end of the index? ...
Hi All, We have a legacy database which is a sql server db (2005, and 2008). All of the primary keys in the tables are UniqueIdentifiers. The tables currently have no clustered index created on them and we are running into performance issues on tables with only 750k records. This is the first database i've worked on with unique id...
Is it possible to convert a clustered index to non clustered index or non clustered index to clustered index in sql server 2005. Please convert this query into clustered index: create index index1 on mytable(firstcolumn) Please convert this query into non clustered index: create clustered index clusindex1 on mytable(cluscolumn) ...
I just realized I have a clustered index on a Timestamp in descending order. I'm thinking about switching it to ascending, so that as new, ever-increasing timestamps are inserted, they are added to the end of the table. As it stands now, I suspect it has to add rows to the beginning of the table, and I wonder how SQL Server handles tha...
How does the PRIMARY KEY keyword relate to clustered indexes in SQL Server? (Some people seem to want to answer this question instead of a different question I asked, so I am giving them a better place to do so.) ...
When a table has a clustered index in SQL Server does that mean that all indexed queries will go via the clustered index? For example if I have a table with a single non-clustered index (indexing one column) and search for a row via that column it will do Index Seek -> RID -> Data row lookup -> Result But if I add a clustered index on ...
My two questions are: Can I use clustered indexes to speed up bulk inserts in big tables? Can I then still efficiently use foreign key relationships if my IDENTITY column is not the clustered index anymore? To elaborate, I have a database with a couple of very big (between 100-1000 mln rows) tables containing company data. Typically ...
I'm trying to work my way through a Java Tutorial. The author wrote the tutorial to work with MS SQL. I'd like to follow the tutorial using MySQL. I'm not completely sure how to translate the MS SQL script which uses "IDENTITY", "CONSTRAINT", and "CLUSTERED" as you'll see below: CREATE TABLE [event_person] ( [event_id] [int] NOT NU...
I now understand that a clustered index contains all of the row data, not just the index fields. I'm trying to understand the implications of this in regards to fragmentation. Say we have a table like this: create table Files ( ID uniqueidentifier not null, Field1 nvarchar(300) null, Field2 nvarchar(300) null, Field3 nv...
I have a table with many columns of which the total max size greatly exceeds the 8k boundary. This table contains a ModuleID column which basically tells u what type of object it is (dont worry - I didnt design this) of which there are maybe 15 different values. And then it has a unique column called propertyID which is also an IDENTITY(...
By default MongoDB creates index on _id key in document. But when I ensure additional index (secondary like in InnoDB from MySQL?) and query it after, engine scans it and then selective scan _id index to get documments offsets? I'm confused because when sharding comes it I'm right every chunk have own indexes and there will be many rand...
One of my co workers is under the impression that when adding an index to a table in SQL Server 2008 that the PK's index is added to that index as well. Therefore if you are using a wider primary key then that key will also be included in the new index vastly increasing the disk space used above and beyond the penalty already paid for th...
Hi, Would like some advice from this. I got a table where I want to keep track of an object and a list of keys related to the object. Example: OBJECTID ITEMTYPE ITEMKEY -------- -------- ------- 1 1 THE 1 1 BROWN 1 2 APPLE 1 3 ORANGE 2 2 W...
I create the following table in H2: CREATE TABLE TEST (ID BIGINT NOT NULL PRIMARY KEY) Then I look into INFORMATION_SCHEMA.TABLES table: SELECT SQL FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = 'TEST' Result: CREATE CACHED TABLE TEST( ID BIGINT NOT NULL ) Then I look into INFORMATION_SCHEMA.CONSTRAINTS table: SELECT SQ...
I want to create an annotated class similar to that: @Entity @MappedSuperclass @Inheritance(strategy = InheritanceType.TABLE_PER_CLASS) public class SeriesMonitoringPointsTable { @Id @Column(name = ID, nullable = false) private Long id; public void setId( Long id ) { this.id = id; } } In this class I woul...
IMO, please correct me... the leaf of clustered index contains the real table row, so full clustered index, with intermediate leaves, contain much more data than the full table(?) Why/when/how is ever whole clustered index scan chosen over the full table scan? How is clustered index on CUSTOMER_ID column used in SELECT query which ...
I've inherited some database creation scripts for a SQL SERVER 2005 database. One thing I've noticed is that all primary keys are created as NON CLUSTERED indexes as opposed to clustured. I know that you can only have one clustered index per table and that you may want to have it on a non primary key column for query perfoamce of searc...