database-partitioning

问题 I am trying to use a partitioned table in postgresql together with a Django installation. From Googleing the subject, I found out, that Django does not support partitioning by itself, so I did the partitioning of the table myself. I partition my table based on a second field which is a foreign key on another table. The basic model setup is like so: class Event(models.Model): id = models.AutoField(primary_key=True) device = models.ForeignKey("Device") ... (More Fields) I have Partitioned the

问题 Setup Cost of Threshold for Parallelism : 5 Max Degree of Parallelism : 4 Number of Processors : 8 SQL Server 2008 10.0.2.2757 I have a query with many joins, many records. The design is a star. ( Central table with fks to the reference tables ) The central table is partitioned on the relevant date column. The partition schema is split by days The data is very well split across the partition schema - as judged by comparing the sizes of the files in the filegroups assigned to the partition

问题 I want to create sqlite partition structure, I created 3 databases, I attached those 3 databases to another database which will be parent with ATTACH DATABASE '1.db' as 1 ATTACH DATABASE '2.db' as 2 ATTACH DATABASE '3.db' as 3 after i .quit the parent database the database attachments detach, How can I keep them attached even if I quit the database? Thanks. 回答1: Attachments are never permanent. Every program that opens the database needs to make any attachments it needs. If you really think

问题 I just went through this tutorial and the bullet on slide 39 stood out: "Do NOT mix partitioned and unpartioned tables in the same server" I don't know what the author is referring to. Does this apply only to benchmarking? Is there some requirement that all tables should be partitioned when you partition one? Even if it only applies to benchmarking, I would still like to know why they all must be partitioned to get good benchmark results. 回答1: Slide 39 has the following title: Benchmarking

问题 I'm trying to create simple table with partitions. this is my command: CREATE TABLE measurement ( city_id int not null, logdate date not null, peaktemp int, unitsales int ) PARTITION BY RANGE (logdate); this is the error I got: SQL Error [42601]: ERROR: syntax error at or near "PARTITION" Unable to understand with is the problem.. I am using PostgreSQL 9.6.3 回答1: "Declarative table partitioning", that is partitioning as a first-class feature of the DBMS with its own syntax, was added in

问题 Executing a regular UPDATE statement on a partitioned table seems to be worst than doing it in a regular one. Setup CREATE TABLE users ( id VARCHAR(10) NOT NULL, name VARCHAR(10) NOT NULL ) PARTITION BY HASH (id); ALTER TABLE users ADD PRIMARY KEY (id); CREATE TABLE users_p0 PARTITION OF users FOR VALUES WITH (MODULUS 3, REMAINDER 0); CREATE TABLE users_p1 PARTITION OF users FOR VALUES WITH (MODULUS 3, REMAINDER 1); CREATE TABLE users_p2 PARTITION OF users FOR VALUES WITH (MODULUS 3,

问题 I know how partitioning in DB2 works but I am unaware about where this partition values exactly get stored. After writing a create partition query, for example: CREATE TABLE orders(id INT, shipdate DATE, …) PARTITION BY RANGE(shipdate) ( STARTING '1/1/2006' ENDING '12/31/2006' EVERY 3 MONTHS ) after running the above query we know that partitions are created on order for every 3 month but when we run a select query the query engine refers this partitions. I am curious to know where this

问题 I'm in the process of building a database storage for my app consisting on a single table with a huge data volume (hundreds of millions of records). I'm planning on having an index on the date field, since I'll be doing a batch recovery of all the records in a given period of time every now and then (for example, retrieving all records for the following day, at midnight). Since the number of records is huge and performance is an important concern in this system, I would like to know if there

问题 I understand that as of MySQL 5.5, you can now partition a table by non-integer values like a varchar. I have a table where I perform a lot of lookups on a single varchar column, hence I would like to partition on that for performance reasons. In all instances, the value of the column is a single alphabetical word (strictly lower case a-z, enforced by validation). What I would like to do is partition this table by the first letter in each word stored, so all words beginning with 'a' go in the

问题 i want to store changes that i do on my "entity" table. This should be like a log. Currently it is implemented with this table in MySQL: CREATE TABLE `entitychange` ( `id` int(11) unsigned NOT NULL AUTO_INCREMENT, `entity_id` int(10) unsigned NOT NULL, `entitytype` enum('STRING_1','STRING_2','SOMEBOOL','SOMEDOUBLE','SOMETIMESTAMP') NOT NULL DEFAULT 'STRING_1', `when` TIMESTAMP NOT NULL, `value` TEXT, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1; entity_id = the primary key of my