A database structure that can improve the speed of queries at the cost of disk space and slower inserts/updates. It stores a copy of one or more columns but structures the data differently to allow for faster access.
0
votes
3answers
18 views
Mysql - How to optimize retrival time in a table
I have query like this! which has 200 million Records in a single table.. I am using BTree Indexes in my table...
mysql> select COUNT(DISTINCT id) from [tablename] where [columname] >=3;
...
2
votes
2answers
105 views
Can I use a foreign key index as a shortcut to getting a row count in an INNODB table?
I have a table that has a large number of rows in it.
The primary key (an auto-incrementing integer) is, by default, indexed.
While waiting for a row count to be returned I did an EXPLAIN in another ...
1
vote
2answers
244 views
Slow insert with MySQL full-text index
I use a full-text index in a MySQL table, and each insert into this table takes about 3 seconds. It seems that MySQL rebuilds (a part) of the full text index after each insert/update. Is this right?
...
0
votes
2answers
39 views
Is there slowdown inserting into an InnoDB table that has no index set?
I have an old application with lots of InnoDB tables, that have no indexes at all, not even a primary ID or such.
Those tables only contain a few thousand rows.
Would it be faster to INSERT data ...
0
votes
2answers
95 views
Indexing a longtext field
I would like to run an index on a longtext field using:
CREATE INDEX post_meta ON wp_postmeta (meta_value(8));
There are currently ~1 million records.
Questions:
Will creating this index affect ...
6
votes
1answer
59 views
Dropping Hypothetical Indexes
In the past I thought I'd deleted hypothetical indexes using either a DROP INDEX statement for clustered indexes and DROP STATISTICS statement for non-clustered indexes.
I have a database that is ...
6
votes
1answer
72 views
Minimizing Indexed Reads with Complex Criteria
I'm optimizing a Firebird 2.5 database of work tickets. They're stored in a table declared as such:
CREATE TABLE TICKETS (
TICKET_ID id PRIMARY KEY,
JOB_ID id,
ACTION_ID id,
STATUS str256 ...
5
votes
1answer
77 views
Efficiently Filter Large Set With Disjunctions
Let's say I have a single table
CREATE TABLE Ticket (
TicketId int NOT NULL,
InsertDateTime datetime NOT NULL,
SiteId int NOT NULL,
StatusId tinyint NOT NULL,
AssignedId int NULL,
...
3
votes
1answer
73 views
In MySQL, does the order of the columns in a WHERE clause affect query performance,why?
I have a query that doesn't use any indexes:
SELECT 32,
guid,
1,
1,
1,
0,
5
FROM test
WHERE level >= 20
AND ( ( fun_GetIndexValue(data, 354) ...
2
votes
1answer
73 views
mysql: need help to optimize my query/table
I'm wondering if someone could help me optimize my tables/query to speed up a query. It is currently running ridiculously slow. I think a well-thought out index could help me. Any help would be really ...
2
votes
1answer
135 views
Bitmask Flags with Lookup Tables Clarification
I've received a dataset from an outside source which contains several bitmask fields as varchars. They come in length as low as 3 and as long as 21 values long. I need to be able to run SELECT queries ...
1
vote
1answer
70 views
I would like to query a range of criteria on multiple columns in MySQL
I have 3 columns in a mysql table. I'm using Innodb engine. I want to be able to search for some values on those columns and also anything close to those values. For example :
We have 3 columns as ...
0
votes
1answer
24 views
Which text-index I should create for xooops engine to achieve better search results?
In one of projects we use xoops engine to manage content. In mysql slow query log most of queries are following :
SELECT p.uid,f.forum_id, p.topic_id, p.poster_name, p.post_time, f.forum_name, ...
0
votes
1answer
69 views
Mysql. Block/disconnect slow queries
I am experiencing issue.
Someone 'attacked' my server: simply by searching the same phrase with multiple requests.
As it is text search request and database indices are not used, the engine searches ...
3
votes
0answers
23 views
custom population of full text index
Is there any way to populate a full text search index without storing the backing information in the database?
I don't mean using remote-blob-storage or FILESTREAM types. The backing information is a ...
3
votes
0answers
78 views
Key Lookup and Full-text index
I have the following query:
SELECT T2.Title
FROM TitleTable T1
INNER JOIN TitleTable T2 ON T2.FKID1 = T1.FKID1
WHERE T1.FKID2 = @ID_PARAM1
AND T2.FKID2 = @ID_PARAM2
AND ...
3
votes
0answers
163 views
Can spatial index be a part of multiple columns index in mysql?
This manual over here is extremely unclear and doesn't even provide some sample SQL statements:
http://dev.mysql.com/doc/refman/5.6/en/column-indexes.html
Another way to rephrase the question is the ...
2
votes
0answers
93 views
Why does CREATE INDEX … WITH ONLINE=ON block access to the table over a period of minutes?
I have an existing table:
CREATE TABLE dbo.ProofDetails
(
ProofDetailsID int NOT NULL
CONSTRAINT PK_ProofDetails
PRIMARY KEY CLUSTERED IDENTITY(1,1),
ProofID int NULL,
...
2
votes
0answers
32 views
How can one improve the performance of a query that selects on a low cardinality column in MySQL?
I have a "State" column that has a low cardinality (three possible value), on which most of my queries perform an equality selection (WHERE col = 'blah') AFAIK you need something like a bitmap index ...
2
votes
0answers
70 views
What is the effect of replacing indexes with filtered (non-null value) indexes?
Our project runs a very large, very complicated database. So about a month ago, we noticed that the space used by indexed columns containing null values was getting too large. As a response to that, I ...
2
votes
0answers
76 views
SQL fulltext indexing ranking combined with ranking used by window's file indexing service
We have a list of records contained within a MS SQL database table, we have enabled "Full Text Indexing" on the table. Also, we have set up a window's file indexing service and added a catalog ...
2
votes
0answers
22 views
Can I read data from a 'hash field' in a legacy Ingres database?
I have been asked to read and present data from the 'hash fields' of an Ingres 2.0 database, which are apparently multiple pieces of data stored together in a single field in various combinations. I ...
2
votes
0answers
77 views
MS-SQL index not using all the available columns as seek predicates
I have a sql query on a large table (>17 million rows) that some times does not populate all the predicates before performing index seek, which results in not filtering out enough rows and slowing the ...
1
vote
0answers
29 views
parenthetic grouping of join clauses
What is the difference between these joins?
a left join b left join c
(a left join b) left join c
a left join (b left join c)
Does the grouping only affect the order of the joins? Will the query ...
1
vote
0answers
87 views
Best Practice to update columnstore indexed tables
I have a table with aprox. 22 Bn rows, for each month I have made one partition that and each partition has two data files. I created the columnstore index on this table and the performance ...
1
vote
0answers
31 views
How does MySQL 5.1 use indexes?
I've read the docs for MySQL v5.1.x on how about the indexes are used, but I'm not sure I understood it properly.
Suppose having the following MySQL table:
CREATE TABLE IF NOT EXISTS ...
1
vote
0answers
1k views
SQL Server Rebuild/Reorganize Fragmented Indexes causes CRC error or consistency errors
In our test lab I've been experimenting with different jobs to keep our critical indexes from becoming too fragmented.
I'm currently using the approach described here: sys.dm_db_index_physical_stats ...
0
votes
0answers
25 views
How to make continues cluster?
I have a report table with the following index:
providerid, date
The table is around 30M records and it grows about 100K rows per day.
I want to use in the index above as a cluster, but as I ...
0
votes
0answers
8 views
Fine grained (milliseconds) temporal indexes in neo4j
What are the best practices for modeling fine grained timelines in neo4j? If I were to use milliseconds as the grain in the pattern described here and here would it prove somehow problematic and ...
0
votes
0answers
21 views
MySQL (v5.6.11) InnoDB 5.6.11 restoring indexes during table copy
When i see the profile for my optimize table query here is what i see for the InnoDB storage engine 5.6.11:
+----------------------+------------+
| Status | Duration |
...
0
votes
0answers
44 views
one vs two column index difference when doing JOIN query?
Let`s suppose that alfa,beta and gamma contains milions of rows so we need to create indexes obviously to get optimal performace for this query :
SELECT * FROM alfa
JOIN beta on beta.id = ...
0
votes
0answers
31 views
The best approach to index dynamic query in MongoDB
I am working on log managment system where user will be able to upload logs from file. I have 'event' collection where I store all events from all sources (each source can have different log format ...
0
votes
0answers
258 views
Having trouble creating a unique key for full-text index on an indexed view in SQL Server 2008r2 and I am not sure if the string length is the cause
I am having trouble creating a unique key for a full-text index on an indexed view. My definition is as follows:
CREATE VIEW [dbo].[vw_inventory_metadata] WITH SCHEMABINDING AS
SELECT ...
0
votes
0answers
141 views
Why this query takes 500 seconds to complete even though I got all the compound index right?
I tried this query
db.tablebusiness.find({ "LongitudeLatitude" : { "$nearSphere" : [106.772835, -6.186753], "$maxDistance" : 0.053980478460939611 }, "Prominent" : { "$gte" : 15 }, "indexContents" : { ...
-1
votes
0answers
43 views
Unexpected index scan against partitioned table
I have a set of partitioned tables with CIX on (ID, DATE) and partitioned on DATE.
There is another identical set of non-partitioned tables with CIX on ID.
Case A: T1 and T2 are non-partitioned ...
