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

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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 ...
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1answer
255 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 ...
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1answer
504 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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3answers
65 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 ...
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1answer
97 views

Archive partition before delete it?

I have manage to create an event and with the following scripts could both create and delete the partition. The issue now I need help on how to save the partition before its deleted? Should I use ...
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3answers
1k views

effective mysql table/index design for 35 million rows+ table, with 200+ corresponding columns (double), any combination of which may be queried

I am looking for advice on table/index design for the following situation: I have a large table (stock price history data, InnoDB, 35 million rows and growing) with a compound primary key (assetid ...
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1answer
73 views

What is a “leaf expression”?

What is a "leaf expression"? Partition-clause expressions are limited in the following ways: Your partition-clause must calculate a single non-null value for each row. You can reference multiple ...
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77 views

Add partition works but not the drop partition

We have set an event as below. What we notice is that the add partition is working well as we can see on a daily basis the partition list is growing but the drop partition is not working well any ...
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2answers
658 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 ...
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333 views

Are there any disadvantages to partitioning on financial year?

Our current set up has one table per financial year (May 1- April 30). Each table has approx 1.5 million rows. We have about 8 years of data, and will obviously be adding each year. The majority of ...
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46 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 ...
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32 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 ...
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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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1answer
669 views

How to take partitions or filegroups out of service

I'm an experienced SQL Server DBA but new to partitioning, and I have a couple of questions. Using SQL Server 2008 R2 Enterprise Edition. I've inherited a large customer metrics database that grows ...
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1answer
48 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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1answer
58 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 ...
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0answers
76 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 ...
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3answers
137 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 ...
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1answer
19 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 ...
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2answers
102 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 ...
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1answer
123 views

Availability Groups and Partition Swapping

Is it possible to use SQL 2012 Availability Groups over two machines and perform partition swapping on the primary machine ?
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1answer
39 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 ...
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1answer
44 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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3answers
13k views

How do I get a list of all the partitioned tables in my database?

How do I get a list of all the partitioned tables in my database? Which system tables/DMVs should I be looking at?
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1answer
190 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 ...
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2answers
235 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 ...
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2answers
629 views

Partitioning a table vs moving entries to another table

I don't understand how partitioning helps me more or less than using a separate table to store older records. I need to maintain a list of stock entries along with historical records about the stock. ...
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1answer
834 views

How to structure Master/Detail tables for performance without denormalizing?

Some Background Info We have a set of tables that holds all the transactions for our system, TransactionHeaders and TransactionDetails. There are roughly 80k Transactions a day which translates to ...
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2answers
1k views

ALTER TABLE SWITCH statement failed

ALTER TABLE SWITCH statement failed because column does not have the same ANSI trimming semantics in tables... Does anyone knows how to fix that on already existing table full of data? Well, I've ...
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1answer
781 views

Indexing issues while partitioning with dbms_redefinition

I get an error while doing the redefinition. Following are the steps which I have taken so far: Step 1. Start redefinition DBMS_REDEFINITION.CAN_REDEF_TABLE(v_name, 'T_FDC_TOOLCONTEXT', ...
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1answer
169 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
2k views

Rename interval partitioning system generated partition names

I have an existing table which I partitioned (interval partitioning on a daily basis) using dbms_redefnition. PARTITION BY RANGE ("TIME_ID") INTERVAL (NUMTODSINTERVAL(1,'DAY')) (PARTITION "p1_1" ...
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1answer
67 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 ...
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1answer
50 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: ...
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242 views

MySQL Read Speed and Partitioning on Separate Drives

Introduction Simple project but for an heavy read load -90% reads- over a table(~20Milion Rows ever-growing where I have to boost performance and ensure response low time for read queries) that was ...
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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 ...
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1answer
131 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. ...
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162 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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138 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 ...
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1answer
187 views

Does partitioning a MySQL table also increase index creation performance?

This is something I was wondering since I'm planning to partition a aggregation table with 10 mil records where rebuilding indexes cause table locks for some time. Because partitions are bluntly put ...
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4answers
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Table partitioning for archiving data

Scenario: two databases: DB_A and DB_Archive with one very big table called tableA. every day, records older than 60 days are deleted from DB_A and moved to DB_Archive mainly to leave thing ...
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59 views

MySQL: Optimizing for large but discrete data sets

In brief: I'm developing a database that handles GTFS datasets from multiple transit agencies. Each dataset contains millions of rows in the stop_times.txt file (and thus its corresponding table). ...
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50 views

Best way set clustered primary key on a partitioned table?

I have the following table. create table T (K1 date, K2 int, K3 varchar(10), C1 int, C2....) The table will be partitioned by K1 (K1 has low selective. the data will be appended in the order by ...
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36 views

How to move partitions between filesystems

We have ~9TB MySQL database which consists from a few tables which are partitioned by day. Sum of daily information is ~20GB. Database is practically write only. There are at most tens of queries ...
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1answer
440 views

Partitioning a Table Referenced by a Foreign Key

I have one table: CREATE TABLE [dbo].[entry] ( [ID] [bigint] IDENTITY(1,1) NOT NULL, [EntryDate] [datetime] NOT NULL, [createddate] [datetime] NOT NULL, CONSTRAINT [PK_Entry_ID] ...
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1answer
65 views

Mysql, sql server, oracle tables get too large [closed]

I hear a lot about things that, it is a lot cheaper to buy new harddisk than pay staff to come up with genius ideas how to save resources. But what I don't understand, is how these databases handle a ...
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46 views

How do I debug an Oracle Linux Diskspace Issue?

I have about 429GB Diskspace allocated to this VM. I see that only 179GB is being used. Now when I try to add a 128GB file I get an I/O error saying I do not have any space left. I need to be able ...
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3answers
2k views

Can I move rows between partitions by updating the partition key?

I would think that this would be a fairly simply question, but I've actually had a difficult time finding an answer for this. The question: Can you move rows of data within a partitioned table from ...
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3answers
959 views

How to partition a table by timestamp, where data from every i'th day goes to partition i?

I'm looking into partitioning a table in my InnoDB database. I have a column corresponding to a UTC timestamp, and I want to partition around that. The basic idea that I want to capture is a ...
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1answer
352 views

partitioning by datetime vs date vs int performance

I am trying to determine which partitioning strategy will be most efficient for my queries on SQL Server. We know we want daily partitions. The data has a natural DATETIME field in it, so my gut ...