The server Microsoft SQL Server 2000 index does not have much change, originally thought will have R-tree, BITMAP index and so on Dongdong come out, the result very let a person lose
Hope: (
However, there are some changes, the third one has said that can be indexed to view, there is a point is that the computed column (computed Columns) index.
？ Do not know what is computed Columns? Aggravation
Actually this dongdong I also used once, copy a paragraph online book's sample code bar
CREATE TABLE T2 (a int, b int, c int, x float,
Y as Case x
When 0 THEN a
When 1 THEN b
ELSE C
End)
CREATE TABLE MyTable
(
Low int,
High int,
Myavg as (low + high)/2
)
See, that is, as the following plus a calculated value, OK, continue
Now, although you can index a computed column, there are some limitations, such as AVG, SUM, and the entire table, and the computed values are not Gazzo
Also, it is not possible to index an indeterminate computed value, and the field used in the expression must also be in this table.
SQL 2000 has some optimizations for the index, but the specifics are not very clear, and all I know is that you can use parallel when indexing on a multiple-CPU machine
Multithreading to scan and classify data. Implementation of the technical details do not have much meaning, a simple introduction is that the server before the index to make a quick random sweep of the table
Strokes, the data is divided into several pieces according to the set parallelism, then each thread uses the filter to query the base table, establish the index structure, each thread is completed and then the
These indexes are connected together.
Many parts of SQL 2000 are optimized for multiple CPUs and clustered servers, but now there is too little information, but it will be discovered slowly for a while.
Next Period Notice
Full-Text Search
Appendix:
function that is not sure of the return value
@ @ERROR
@ @IDENTITY
@ @ROWCOUNT
@ @TRANCOUNT
App_name
Current_timestamp
Current_User
Datename
FormatMessage
Getansinull
GETDATE
getUTCDate
host_id
Host_name
Ident_incr
Ident_seed
IDENTITY
Newidpermissions
Session_user
Stats_date
System_user
Textptr
Textvalid
User_name
