indexing

Can dropping and recreating an index speed up a SQL delete?

I'm performing some large date-based delete queries on tables with indexes on fields other than date. I've been told that dropping those indexes, performing the delete, and then re-building the index could be faster than just running the delete against the indexed table. Is this the case? I can see why the actual removing of records wou...

Merge two XML Documents(same core text,diferent tags) to index on Lucene

Hello comunity! ;) I'm building a web search application (rich application) that is intended to search over some historical documents. Those documents have their own structure. I'm using lucene 3.x to build the search engine, etc. So far i have built my own Analyzer and a SimpleToken class to fit my needs. So what is the problem? The ...

Rails/Indexes performance Q - which is faster?

Table has columns: user_id and season_id Which is faster: #If I have a database index on user_id Table.find_all_by_user_id(some_id) or #If I have a database index on user_id and season_id Table.find_all_by_user_id_and_season_id(some_id, another_id) Is a multi-column index always faster? For example, is writing a multi-column index ...

C Program - Build an index file from another file

I have a .bin file that contains records in CSV format what I want to do is assign each record in the bin file a sequence number. So the first record in the bin file would be assigned 0 and so on. These will be placed into a bianry index file such as (username, seq #). If I have the bin file already created with records in it, how d...

Indices and capped collections with MongoMapper

What is the best way to set up an index or configure a capped collections in a Rails project? From what I've found, it seems that a good way would be to keep this configuration in an initializer. The command for setting up an index is ModelName.ensure_index :key, but what is the command for a capped collection? ...

C program: How to read from one file and write into another? Indexing

I am trying to write a program that will read the existing records of a file and then index them in another file. The records are stored in the file named "players.bin" which is CSV format each record contains (username,lastname,firstname,numwins,numlosses,numties and i want to index them in a new file named "players.idx". However the ...

Is there a reason for a Primary Key column that would never be used?

I have a routine that will be creating individual tables (Sql Server 2008) to store the results of reports generated by my application (Asp.net 3.5). Each report will need its own table, as the columns for the table would vary based on the report settings. A table will contain somewhere between 10-5,000 rows, rarely more than 10,000. Th...

Drupal 6: Search index and custom content types

Sorry, if question is too obvious — does Drupal 6 index nodes with custom content types, not only story, page, etc.? ...

PropertyInfo.GetValue() how do I index collection by string using reflection in C#?

Hi Guys. Let's say I have a class, which has a NameValueCollection property. public class TestClass { public NameValueCollection Values { get; private set; } public TestClass() { Values = new NameValueCOllection(); Values.Add("key", "value"); Values.Add("key1", "value1"); } } I know how to get...

Documents failing to save to solr using PHP SolrClient

Hi, I've got a bit of a problem that I can't seem to get to the bottom of. I'm a bit fo a Solr Noobie so stick with me here. I am writing a script to populate a solr instance with a small subset of documents, around 250 using the PHP SolrClient. The script runs through and seems to be populating fine. However my document count nev...

How much extra storage does MySQL fulltext index consume?

I am looking for a way to estimate how much extra storage will be needed if a MySQL TEXT column gets a fulltext index. Intuitively speaking the size of the fulltext index is dependent on the total length of text but what exactly is affecting it? ...

How do I create an index in PostgreSQL based on lowercase only?

How would I set up an index based on lower case only? Even though the actual field contains both upper and lower case letters. Also, can I run a query and have only the lower case index value returned? Thanks-- ...

phpMyAdmin wants to add multiple indices as one multi-column index

Hey, I'm creating tables using phpMyAdmin and want to define two different columns as indices. I'm not trying to create a multi-column index but phpMyAdmin creates them as such. Are there any possible issues with that? The fields don't relate to each other directly and both fields will not be used in WHERE clauses simultaneously. Consi...

SQL server filtered indexes

Hi, I have a table that is quite modest in size at the moment but will grow to a few million rows so I’m looking to build things right from the start. The table contains 15 or so column containing information for agent telephony performance but that is not really relevant. One of the queries that is run on this table looks at data from...

Does googlebot crawl urls in jQuery $.get() calls and can it be prevented?

Hi, I have a page that has a form using this ajaxForm jQuery plugin. The form submits, and when it's complete, there is a call using $.get() to load some new content to the page. My problem is, the Googlebot "appears" to be indexing the url in the $.get() method. My first question is, is that even possible? I was under the impression...

how to get index keys from mysql index?

i have an innodb mysql table with a varchar(100) field called 'word'. i created a btree index on an that field. if i do a query like select * from table where word = 'non-linear', i get all variations of that word. so results would include (Non-linear, Non-Linear, non-Linear, etc...). it seems to me that that index doesnt care about ...

mysql binary comparison doesnt use index

I have the following query: EXPLAIN EXTENDED SELECT * FROM ( `photo_data` ) LEFT JOIN `deleted_photos` ON `deleted_photos`.`photo_id` = `photo_data`.`photo_id` WHERE photo_data.photo_id = 'UKNn' AND `deleted_photos`.`photo_id` IS NULL I unfortunately have to use binary to compare this photo_id (which is being handed to me from a diffe...

Reasons not to have a clustered index in SQL Server 2005

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...

Thinking Sphinx Rake aborted, searchd is running whilr rebuilding or start/stop ts. Index works fine.

When I invoke rake ts:rebuild RAILS_ENV=production, I get the following: (in /var/www/abc.com/public/abc/releases/20101008073517) ** Erubis 2.6.6 Stopped search daemon (pid 22531). Generating Configuration to /var/www/abc.com/public/abc/releases/20101008073517/config/production.sphinx.conf Sphinx 1.10-beta (r2420) Copyright (c) 2001-20...

No direct access to data row in clustered table - why?

[11] tells: "In a nonclustered index, the leaf level does not contain all the data. In addition to the key values, each index row in the leaf level (the lowest level of the tree) contains a bookmark that tells SQL Server where to find the data row corresponding to the key in the index. A bookmark can take one of two forms. If the...