Splitting a database table into multiple segments for performance or manageability.

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289 views

Is DBCC SHOWFILESTATS an accurate way to see unused space?

We have a few tables each with near 100 million rows of data. A co-worker has these tables setup with partitions based on a date field. Our disk space is starting to run low and knowing that ...
1
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1answer
124 views

PostgreSQL partition pruning?

In postgres partition is done by child tables. My problem are, when we issue a query to master table , does the query optimizer do partition pruning ? i.e select appropriate child table rather than ...
1
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1answer
28 views

Are there any inherently non-partitionable datasets?

Are there any practical datasets that, by their nature, cannot be partitioned in any practical way? I am wondering about this because such datasets would be ill-suited to scaling out on commodity ...
-1
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1answer
227 views

Oracle Partition Table Space Issue

I have a table with list partitions on it. When i insert data i see that all the partitions have default initial size of 8 MB and I also noticed that when i truncate full table and check size it still ...
2
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1answer
24 views

remove a paritition table

I need to remove a partition table for an application upgrade. It is SQL Server 2008 R2. The partition column is on column col1 data type smallint, null. Col1 has length 10 and precision 5. As you ...
2
votes
1answer
65 views

Best Practice in storage allocation for compressed and partitioned tables

I have a fairly large database that basically consists of one table, this table is paritioned by month and all partitions are compressed with page compression. After the initial load of the data there ...
0
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0answers
34 views

Modulus calculation for compound primary keys in MySQL Cluster (and other sharded databases)

In MySQL Cluster, and generally in sharded databases, how is a compound primary key's modulus calculated? Say, for example, there are two tables that have primary keys like so: CREATE TABLE Orders ...
0
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1answer
40 views

MySQL 5.1: How to rollback partitioned table

I have partitioned a table on the basis of one flag column have value either 0 or 1. Now, I want to roll back these tables. How can I do this?
3
votes
1answer
83 views

Drop partition scheme with orphan indexes

I have a partition scheme in my SQL Server database that I am trying to drop. This scheme was used by 2 indexes, which I deleted. I can't delete the scheme, since it appears to still be used by the ...
0
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1answer
74 views

Oracle DB - Is it possible to distribute data of a table onto multiple servers?

BigTable[1]-like systems (HBase[2] for instance) allows a table to be distributed transparently accross multiple servers. This works as follows: Each server perform the read/writes operations on ...
0
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1answer
116 views

How to split the Wordpress database?

FYI - I originally posted this question under the Wordpress Development site here: http://wordpress.stackexchange.com/questions/145861/how-to-split-the-wordpress-database I have a site that is used ...
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0answers
86 views

Greenplum's poor dynamic partition elimination

I have large fact tables in Greenplum with many years of history that are partitioned by a surrogate key (which represents time). Of course almost all queries are for recent time periods where the ...
0
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1answer
25 views

whether to merge partitioned table with only partially overlapping columns

I opted for MonetDB for my static data, but this might be less of a MonetDB-specific question about features than about RDBMS (or just SQL) in general. I have data with a few "cross-sectional" ...
0
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1answer
1k views

Partition by year and sub-partition by month mysql

I have a database with a date column having datatype as date. I am using mysql 5.6 The table is expected to have 10k rows each day. I want to create partition on the table on year range and then sub ...
0
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1answer
648 views

How to get accurate row counts in partitions in a table

I am trying to fetch row counts in each partition for a table. But I got confused as in sys.partitions row counts is on basis of indexes. So how can I get exact row count for partitions in a table.
3
votes
1answer
220 views

Partitioning large mysql table

I have a large (40GB) table I would like to partition. The rows are essentially write once read many. Currently I am using mysql 5.5 innodb with file_per_table. It's tough to optimize this table since ...
0
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1answer
54 views

Does partitioning sometimes require denormalization?

Specific example of what I'm asking: Say that a SaaS app has an Order table with CustomerID and a child OrderItem table. We want to partition both tables and we want to use CustomerID as the ...
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0answers
66 views

dynamic sql: merge partitioned tables (annual tables into a single table of all years)

I need to merge (UNION) data from annual tables into one large table. I am confused about how dynamic SQL (or else) should be used for this. Below is an updated version of my question on ...
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0answers
44 views

MySQL 5.6 TO_DAYS partitioning schema always searching in first partition for queries which include <,> or BETWEEN operators in where clause

I have this table definition: CREATE TABLE ClientInfo ( IPAddr VARCHAR(16), RepDate DATETIME NOT NULL )ENGINE=MyISAM; PARTITION BY RANGE(TO_DAYS(RepDate)) (PARTITION pNULL VALUES LESS THAN ...
0
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1answer
36 views

How does partitioning and the lack of a primary key affect ON DUPLICATE KEY UPDATE

Consider a table with the following columns: phone BIGINT NOT NULL PRIMARY KEY, name VARCHAR(64), state VARCHAR(64) We would like to partition the table on state, however that would require ...
0
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3answers
384 views

Is table partitioning improving performance? Is it worth it?

I have just been involved in a project on which I will have to develop a data migration process and a web interface that uses an already existing SQL Server DB. This DB was developed by another person ...
2
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0answers
2k views

Sharding Postgres Database

I have a Postgres database that has grown to the size where it is no longer feasible to store everything on a single database node. There is a Customer table in my schema where each row represents a ...
10
votes
1answer
186 views

How can I interpret the results of these DMVs to help me evaluate our partitioning strategy?

Version: SQL Server 2008 R2 Enterprise Edtn. (10.50.4000) In attempt to evaluate our partitioning strategy, I wrote this query to get the access methods against indexes on partitions (in the broadest ...
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2answers
72 views

Oracle tables partition related

Here is my doubt. Is it possible to apply a partition to one table depending in the partitions values of another one? Why I am asking? I have one table where information headers are persisted, and ...
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1answer
67 views

Partitioning a table state

So far I always used date ranges to partition my tables, however now I like to do it by state or a selected list of cities where all others that are not explicitly listed in an "other" partition, is ...
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2answers
97 views

What are the possible risks involved in partitioning large database tables? [closed]

There has been much talk about the benefits of table partitioning in Relational DBMS. I would like to know: Are there any risks to table partitioning ? What measures are there to take to minimize ...
0
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1answer
167 views

Is searching an alternate index on a partitioned myISAM table concurrent or serial?

I have a myISAM table with 30 partitions. The primary key is a SHA1 hash value, which is also used in the partition selection function. I also have an alternate key - an autoincrement integer. Since ...
3
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1answer
72 views

What inefficiency does sharding & partitioning attempt to address? [closed]

I have never implemented sharding or partitioning, but from what I understand, multiple servers are used to distribute large amounts of data. Is this because of a limited hardware budget or to ...
1
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1answer
21 views

Logically Horizontale-Partitioned Tables

I have two legacy tables, lets call them TableA and TableB. Both of them fall under the same schema design with identical columns, in other words you can union them directly as one table. The only ...
3
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3answers
1k views

Best practices for configuring the Drive/Filegroup setup for Microsoft SQL 2008

I am a software developer for a small company. I wish we had a dba but not in the cards at this point for this company. I was working on migrating our 75gb SQL Server 2000 database to SQL Server 2008 ...
2
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2answers
353 views

Return ID from partitioned table in postgres?

When I insert a record I need to return the inserted id by RETURNING. The problem is that the table is partitioned and in partitioned table I can't use RETURNING. I run multiple queries at once so I'm ...
0
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1answer
123 views

What is the best partition technique for large table with TEXT column?

MySQL: What is the best partition technique for large InnoDB table (around 1.5M rows) with TEXT type of column? There is a FULLTEXT index on the TEXT column, which is very essential for my searching ...
0
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1answer
82 views

Does Oracle Partition by Reference optimizes join queries

Oracle 11g has a new feature in partitioning tables called partition by reference. I want to know whether Oracle joins (nested-loop-joins or hash-join or ...) rows from proper partitions when joining ...
2
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2answers
153 views

Partition : understanding files and file groups

We are trying to partition a large history table. Being new to partitioning, I was trying to understand the concept of files and file groups. File groups can be set up in following three ways : 1. ...
0
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1answer
57 views

Proper drive partitioning in Linux for Oracle

I have a current production physical server running on RHEL and I'm going to be building a new Oracle Linux VM to take it's place. Below is a listing of the existing physical drive partitions. Can ...
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0answers
241 views

Storing and querying rolling data in PostgreSQL

I have a large quantity of weather model data being put into a PostgreSQL database. The machine has 8 cores and 16 GB of RAM. I'm running PostgreSQL 9.3 with PostGIS 2.1. Each table will have a ...
5
votes
2answers
635 views

Oracle partition by interval using persian calendar

Oracle supports Persian (Jalali) calendar in DDL queries, I can easily say: select to_char(register_date, 'YYYY-MM-DD', 'nls_calendar=persian') from my_table; I created a table as: create ...
6
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1answer
734 views

How accurate is the sys.partition.rows column?

The system view sys.partitions has a column "rows" that is the total number of rows in a given partition. For a table that is not partitioned (or only has one partition depending on how you look at ...
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1answer
218 views

Postgres: Put 1 database in separate HD partition?

I have 2 HD partitions - one with SSD and another with regular hard drives. I have multiple databases (as in logical database, not physical) with 1 data directory. I want the data for 1 of the ...
0
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1answer
2k views

Database partitioning - Horizontal and Vertical sharding - Difference between Normalization and Row Splitting?

I am trying to grasp the different concepts of Database Partitioning and this is what I understood of it: Horizontal Partitioning/Sharding: Splitting a table into different tables that will contain a ...
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2answers
269 views

Snapshotting Database Tables

I have a reporting database (in SQL Server) that takes nightly snapshots of the production data (Oracle) for users to query against for the next day, but now the requirement is getting to be that they ...
0
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1answer
78 views

Constrain exclusion to fetch latest N rows

I'm managing a table with several million records which are being inserted in real time. A part of my app needs to display the last N inserted records, so at the beginning I just queried for: ...
2
votes
2answers
434 views

Creating a partition on my soft-delete indicator column

In SQL Server 2008 R2 I am exploring the use of partitioning tables. We have a soft-delete scheme which is sometimes an IsDeleted bit NOT NULL and sometimes a DateDeleted date NULL I want to focus ...
3
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0answers
220 views

PostgreSQL 9.2 - Partitioning: Constraint Exclusion on SELECT not kicking in [closed]

My partitioned table SELECT queries include all partitioned tables even though checks are in place and constraint_exclusion = on. The insert trigger works fine and new rows are inserted into the ...
2
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1answer
499 views

Partitioning MySQL vs PostgreSQL

For our new system we are looking for database server. We considered a lot of pros/cons for MySQL(InnoDB) vs PostgreSQL and the breaking point for us is partitioning. We will choose the one which ...
0
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2answers
4k views

Oracle: adding subpartitions to existing partitioned table

In Oracle 11g, is there a way to introduce subpartitions into an existing partitioned table? I cannot seem to find a combination of EXCHANGE and SPLIT partition that does the right thing. SPLIT will ...
4
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1answer
278 views

Large difference in disk space used by partitions

I have a partitioned table that contains about 155 million records total. It's partitioned by year and the partitions for both the current and previous years contain about 25 million records each. ...
5
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0answers
250 views

Should I group by and then join, or join and then group by?

(oracle's optimizer does the same thing for both approaches when just two tables are involved, thus my question involves three tables) Assume three tables t1, t2 and t3 with a pairwise 1:n ...
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2answers
302 views

Is database partitioning for performance reasons meaningful in virtualized environment? [closed]

When running SQL Server on real hardware partitioning database and placing different partitions with different tables on different hard drives can be beneficial for query performance. Or, to simplify ...
0
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1answer
476 views

Bulk loading to partitioned table

I am designing a database application which will be using PostgreSQL 9.3. My question is regarding bulk loading a CSV to a partitioned table. I have done a lot of research, but I'm still unsure of ...