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1answer
310 views

Query_cache doesn't work with join

I have a simple join query, but for some reason query_cache won't cache it! SELECT id, news, approve, FIXED, DATE, allow_main FROM post LEFT JOIN post_plus ON post.id = post_plus.news_id WHERE ...
1
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1answer
791 views

MySQL: To use MYISAM or INNODB engine? (plot twist enclosed)

We use INNODB for all of our tables, but I have one special table, a 100+ GB reference table (only read-queries against it). We are loading changes to this table in a nightly batch job using LOAD ...
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2answers
4k views

Cache all mysql table

Maybe it sound's like i'm an idiot... But i'm developing app with huge db on RoR. Also i see that if i do some query and after that do it one more it is doing much faster, becouse it has been ...
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1answer
55 views

Caching A Query Daily

How to ensure a query runs only once a day in MySQL? Once it runs, returned result should be cached, and even though returned data were changed in database, my query's results should remain the same ...
1
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1answer
39 views

Reducing query cache for mostly INSERT-heavy database?

What sort of MySQL query cache should I choose considering the following... Large, rapidly growing database (I got 500,000 rows). UPDATEs practically never happen. SELECTs are rare, but when they do ...
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1answer
35 views

MySQL - stay in cache priority for queries

Is there a way to tell MySQL that some queries has highter priority in cache and mustn't be popped out until it's data become invalid? The problem is that innodb cache size is rather small and data ...
1
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2answers
154 views

How to determine if open_table_cache is set properly?

Does anyone know what this really means? (from MySQL docs) You can determine whether your table cache is too small by checking the mysqld status variable Opened_tables, which indicates the ...
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2answers
600 views

Oracle 11.2 using too few memory

it is about one year that I have changed my server from Oracle 10g to 11.2g (and also changed the hardware and Windows from 2003R2 to 2012). The problem is that with more than doubled cpu power, ...
1
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1answer
84 views

If MySQL isn't caching, then what is?

I ran a few commands to see whether MySQL is caching queries/result sets. It looks like this is not the case. mysql> show variables like 'query_cache_size'; -------------- show variables like ...
1
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1answer
246 views

Command line switch to disable Coherence?

We have a Java app that happens to have the coherence jar in the path. My application doesn't need it, so I'd like to pass some type of -D variable to the JVM to tell it to ignore coherence, or ...
1
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1answer
511 views

MySQL: How do I limit or prevent caching for specific tables?

I'm currently working on a database schema for tables to hold user information on a website with integrated forums. Right now my idea is to have all the data in two separate tables: one table with ...
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0answers
103 views

What causes the creation of such a large number of Galera cache files?

I manage a Percona XtraDB 3-node cluster. Recently the MySQL datadir of one of the nodes (not the one from which the cluster has been bootstrapped) started being filled up with gcache.page.00nnnn ...
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0answers
106 views

Do you need external caching for a Postgres database?

I am currently building a server and have just written a database connection using JDBC, Jooq, and added a DAO layer, which also handles transaction management. I remember that databases can cache ...
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0answers
552 views

Reducing the size of a PostgreSQL Database, utilizing a process other than full VACUUM

We have a Postgres 8.4 installation which hosts both our Defect tracking and Code management (Surround) systems. We are looking at converting and migrating Surround to MSSQL on another server. Our ...
1
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1answer
101 views

Is it normal that I have to FLUSH QUERY CACHE once every 6 hours to maintain fast queries?

I am running MySQL 5.5.37. I have a cronjob set to run every 6 hours to flush the query cache. I realized that if I don't do that, then the cache becomes fragmented and average query response time ...
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0answers
61 views

Flush procedure cache or drop and create?

Okay I had a very strange issue today on SQL Server 2005. We had a stored procedure update that added new parameters to part of it. One database out of ~150 or more seem to not work properly. Using ...
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0answers
745 views

SELECT + INSERT + Query Cache = MySQL lock up

MySQL server seems to constantly lock up and stop responding on certain types of queries and eventually (after couple of minutes of not responding) give up with an error "MySQL server has gone away", ...
1
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1answer
791 views

Temporarly disable cache in oracle 11g

I want to disable the caching for my session in oracle 11g to see how long a query takes. Is this possible or is there a better way for meassuring the time a query takes to run?
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1answer
2k views

What are the pros and cons of using CLIENT_RESULT_CACHE_SIZE and RESULT_CACHE_MODE

I have multiple questions For Oracle Database 11g Release 11.2.0.1.0 what are the benefits of using CLIENT_RESULT_CACHE_SIZE and RESULT_CACHE_MODE. How will the CLIENT side cache be kept sync if ...
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1answer
1k views

Calculating time spent on query cache lock

How can I calculate the total time my MySQL database is spending Waiting for query cache lock ? I've found two specific very simple tables that adding a SQL_NO_CACHE drastically improved the ...
0
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2answers
56 views

MySQL query cache with time based expiration

The database we use has a read and write intensive load. Some read queries are heavy. Unfortunately the Query Cache cannot be used as it is invalidated too quickly. We wanted to avoid the classic ...
0
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1answer
91 views

MySQL Query Cache - what type of queue is used?

I am wondering what type of queue is MySQL Query Cache using. When there is new query and cache is full which query is deleted? Oldest one? One with fewer number of hits? Or maybe there is some ...
0
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1answer
135 views

Does SQL Server cache data results for DAO?

I was surprised to be confronted with the idea that using .NET and DAO one could make use of the SQL Server data cache in a way not at all possible with stored procedures (which benefit from the plan ...
0
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1answer
53 views

Oracle scheduler chain priority in data warehouse applications

The scenario is as follows: We have a data warehouse type application that relies on the Oracle job scheduler and a Chain. This chain is responsible for generating materialized views (caches) that ...
0
votes
1answer
192 views

Why is the result cache always disabled in Oracle 11g

I'm trying to enable the result cache in Oracle 11g. I have used Enterprise Manager to change the result_cache_max_size and result_cache_max_result values to '1M' and '100' respectively (maybe these ...
0
votes
1answer
44 views

Cache statistic data in SQL Server

Currently my team develop additional web app to let customers analyze user statistics to theirs portals. So we have a table with all logins. It contains about 100 millions of rows. One user could ...
0
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1answer
64 views

Confused over table_open_cache

I've been reading about the table_open_cache and I'm slightly confused about how big it should be, I've seen conflicting advice. My DB is running on MyISAM and has 199 tables. I ran into an issue ...
0
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1answer
565 views

Lowering MySQL Memory Usage without Restart

We are using Percona Server 5.5.35-rel33.0-611.precise with InnoDB in our production server. Recently Mysql memory went high and it did't drop from there. We are afraid whether it would result in OOM ...
0
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1answer
392 views

Pagination, check number of selected records

I am working on pagination for a complex join query and unfortunately I am not sure what's the best way to go... Right now I am thinking about the following solution. Imagine that SELECT id... is the ...
0
votes
1answer
400 views

Columns count in SELECT query and SQL Server buffer cache

Let's assume that I have a table with 30-50 millions records. It has ~40 columns. Currently when I request data it always requests all columns because of legacy ORM that we use. I know that if we ...
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0answers
11 views

Different insert operations with the same data and cache

I want to perform several different insert operations into a Postgres database. PostgreSQL Version 9.5. Operating system: SLES 12. I have 200000 rows of data. It is the same for every different ...
0
votes
1answer
43 views

Memory usage of MongoDB

I've got Django app with mongoengine, which executes some aggregation-queries often enough. The main problem is that mongod takes all the RAM and then crashes, so no LRU working, mongod just trying ...
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0answers
35 views

What can cause the the table cache in MySQL to consume much memory?

I have a server with a table_open_cache of ~2000, and a query cache of ~128M. We have ~350 InnoDB (no MyISAM) tables; innodb_file_per_table is disabled; there is no partitioning; MySQL is 5.6. After ...
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0answers
23 views

installed 2012 SP3 after fixing missing cached installer files, @@ version shows up as sp1

I was to upgrade stg server running SP1 2012 standard, upon getting downtime on the first try I received multiple errors about missing installer cached files (.msp), which was fixed using Microsoft ...
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0answers
23 views

How can I cache queries in sqlalchemy just like I do it in mysql by using SQL_CACHE keyword?

I want to cache sqlalchemy,i have discovered that using keyword SQL_CACHE in mysql can be helpful in caching queries on demand. But how do i do it in sqlalchemy ? Is it possible ?
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votes
1answer
52 views

Mysql only using 10% of cache [duplicate]

I have a dedicated Mysql server that only uses 1.1 GB out of 16 GB ram (picture link 1). I belive this leads to my Disk I/O utilization beeing at 75% peaks (picture link1). How can i configure sql ...
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0answers
15 views

Optimise communication to check record status

Imagine an universe full of products. I have an app that electronically marks products and saves this status into the server DB. The app may be used from different devices so each one will mark ...
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0answers
29 views

Database cache problem

I have server based on Linux 64 Bit centos 6.5 and Mysql innoDB engine I created database for php script require database installation , after i successfully finished installation for first time i ...
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0answers
31 views

Should store procedures be cached?

Should store procedures be cached in MySQL? If so, How long it is stay in cache? In my case, When I call one stored procedure first time, it is giving me results in 1 second, after that it gives me ...
0
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0answers
247 views

Req: Typical location of mysql query cache

My MVC framework (CodeIgniter) wants to know where my database (mysql 5.5) writes its query cache. My Ubuntu installation is unexceptional. Would that be /var/lib/mysql/ or further down the chain, ...
0
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1answer
156 views

getting error while installing memcached_function

now i am working with memcached with mysql cluster 7.2 for that i am installed libevent-1.4.14b-stable.tar.gz memcached-1.4.5.tar.gz libmemcached-0.8.tar.gz then ...
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votes
0answers
110 views

Why is LRU is not suitable for joining 2 relations in DBMS [closed]

In DBMS, can someone please explain how the LRU (least recently used) buffer replacement policy acts when joining 2 relations in a database? I have read that LRU is not efficient when joining two ...