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Index= <th scope="col"> ?

P: n/a
Is an index in a database the equivalent for a <TH scope="col"> in a column
of a
table in the html code?

--
Luigi ( un italiano che vive in Svezia)
https://www.scaiecat-spa-gigi.com/sv...or-italien.php


Jul 23 '05 #1
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P: n/a
No. TH is essentially a bolded TD tag. In MSSQL, a table w/o a
clustered index is a "heap", the rows are in random order. A table
with a clustered index, physically stores its rows in the clustered
index and is ordered by the index keys. A non clustered index is based
off the clustered index (if there is one). The reason why indexes are
important is that the data lives on disk. The database doesn't load
the entire table into memory, waiting for you. When you perform a
query, it goes out to disk and fetches a subset of rows, hopefully by
using a index. Otherwise it has to scan the entire table. (Try
scanning a phone book. It's not much fun if it isn't sorted.) If you
want an analogy, an index is more like a memory pointer. I don't think
it's possible to explain indexes in one paragraph. Suggest reading up
on it in Books On Line.

Jul 23 '05 #2

P: n/a

"louis" <lo************@gmail.com> skrev i meddelandet
news:11**********************@z14g2000cwz.googlegr oups.com...
No. TH is essentially a bolded TD tag. It seems to be more than that

http://www.w3.org/TR/REC-html40/stru....html#h-11.4.1
In MSSQL, a table w/o a clustered index is a "heap", the rows are in random order. A table
with a clustered index, physically stores its rows in the clustered
index and is ordered by the index keys. A non clustered index is based
off the clustered index (if there is one). The reason why indexes are
important is that the data lives on disk. The database doesn't load
the entire table into memory, waiting for you. When you perform a
query, it goes out to disk and fetches a subset of rows, hopefully by
using a index. Otherwise it has to scan the entire table. (Try
scanning a phone book. It's not much fun if it isn't sorted.) If you
want an analogy, an index is more like a memory pointer. I don't think
it's possible to explain indexes in one paragraph. Suggest reading up
on it in Books On Line.


Any book that you would recommend?
--
Luigi ( un italiano che vive in Svezia)
https://www.scaiecat-spa-gigi.com/sv...i-italien.html



Jul 23 '05 #3

P: n/a
Guru's Guide to Transact-SQL by Ken Henderson. He has 3 books, talking
about MSSQL peculiarities.

On Technet, there is a free online copy of the administrator's pocket
consultant.
http://www.microsoft.com/technet/pro.../adminpoc.mspx

Jul 23 '05 #4

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