Questions tagged [cache]
A cache is a mechanism for temporarily storing (caching) data in memory in order to reduce access time to data stored on disk drives.
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questions with no upvoted or accepted answers
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Does MySQL/InnoDB use table caches when dealing with foreign tables?
TL;DR: Does a table referred to via schema.table get held in table cache?
I have a large number of client databases that our application connects to based on an http request. These are used for every ...
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3
votes
0
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579
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Should Azure host write-caching be enabled when using MongoDB's WiredTiger storage engine
I have several virtual machines on Azure running a mongoDB replicaSet with the WiredTiger storage engine. I'm not sure about the proper host caching option to set on the disks that contain the MongoDB ...
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2
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111
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Source (eg.statement) associated with security memory cache entry (USERSTORE_TOKENPERM / TokenAndPermUserStore)
We are having a security memory cache bloating issue, known as USERSTORE_TOKENPERM or TokenAndPermUserStore. At two different instances (SQL Server 2019, SQL Server 2014 – patched to the latest SP &...
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2
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1
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Caching queries that last longer then then X seconds
Let's assume that I want work with query cache enabled. For example let's set it to 128mb value but my working enviorment is very random and dynamic, so cache is full in 1 minute after setting it.
...
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2
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0
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MongoDB + WiredTiger cache usage stuck on 95%
I'm running a mongo 3.4.7 cluster (8 CPU, 120GB ram, primary + 2 secondaries) with ±130 open connections, each one of them to a separate DB with ±50 collections.
After a few minutes of running, cache ...
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2
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0
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798
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SELECT stuck giving results from the query result cache, though table has changed
A process that runs every two minutes or so started to misbehave. We noticed it was because the cursor fetched repeatedly 0 rows, even if indeed there were new rows satisfying the conditions in the ...
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2
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0
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164
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mysql vs mongodb cache/load balancing
I have a system where users can 'like' content. There will likely be many hundreds of these likes going on at once. I'd like it to be AJAX driven so you get an immediate response.
At the moment I ...
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1
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4
answers
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Buffer Pool caching in Sql clarification
I might sound a little naive to ask this question but I couldn’t find out the answer anywhere.
So my understanding is that the buffer in a sql db maintains disk pages in cache so that when a query ...
1
vote
1
answer
645
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How to check how many keys stored in Aerospike?
I am new to Aerospike and exploring AQL and ASADM.
I Executed command "show sets" and got response -
aql> show sets
+------------------+-------------+---------+-------------------+--------...
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0
answers
251
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How to prioritize indices in Postgres cache?
The server config:
RAM = 16 GB
#CPUs = 6
The Postgres config:
There is only 1 Postgres instance. I.e. no partioning, no clustering, ...
shared_buffers = 5GB
work_mem = 10MB
maintenance_work_mem = ...
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1
vote
0
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MariaDB 10.3.27 - 100% Temporary tables created on disk despite/because of InnoDB?
I am using Mariadb 10.3 with InnoDB with a fairly high load. For some reason, I have 100% of my temporary tables created on disk, despite using Innodb and a large tmp_table_size (2G) (see Mysqltuner....
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1
vote
4
answers
385
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Load index to cache is not using memory available in the key_buffer_size variable
Good afternoon folks,
I have a problem when trying to load the indexes from the MyISAM tables into MySQL memory, even though there is space available in the key_buffer_size variable, it stops loading ...
1
vote
0
answers
558
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Why did mongoDB reads from disk into cache suddenly increase?
This is a mongoDB replica set with 1 primary, 1 secondary and 1 arbiter.
Suddenly the reads from disk into cache and cache page evictions increased 2x-3x and stay elevated since then (all metrics ...
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1
vote
2
answers
1k
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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 ?
1
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0
answers
988
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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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0
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623
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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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1
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0
answers
3k
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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 ...
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1
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0
answers
1k
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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", ...
- 111
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0
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38
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Why MongoDB getting higher memory usage?
This is the sample Python code that I used to write data in MongoDB database. After every connection close, I restart the program and I noticed an accumulation in memory count in the Task Manager. ...
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0
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88
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Disk based Key-Value store to use as LRU cache?
I am looking for a key value store to use as a LRU cache for my application. It needs to hold a lot of data (100G - 1000G) which is why I say disk based. Things I have found via Google seem to be ...
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0
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Keeping up-to-date values aggregated based on some time period
I'm considering a few solutions for a problem involving some sort of a time series data. Imagine: you have a system that keeps track of financial transactions in multiple currencies. To keep it simple,...
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357
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PostgreSQL cache function return value
Suppose I have defined a function that is expensive to compute. Is there a way to define an index in PostgreSQL to cache the return value for a given set of parameters?
For example, let's say that I ...
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Postgresql POD Master/Slave don't clean the cache when Client stopped sending data
I'm running a Performance Stress test on our backend (NODE JS) using a client(JAVASCRIPT) that generates the stress , with a Postgres DB.
I've stopped the client from sending data after 5-6 hours , ...
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0
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1
answer
234
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Does daily pg_dump mess up postgres cache?
I migrated my geospatial Postgres 12.5 database to another cloud provider. I use postgis and I have around 35GB of data and 8GB of memory.
Performances are way worse than on my previous provider, and ...
- 101
0
votes
2
answers
615
views
SSRS Report returning old data
I have created and tested a report in Visual Studio and it returns data from a SQL server database.
Once uploaded to SSRS, the report returns old data.
What would I need to check as it appears the ...
0
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0
answers
198
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Firebird begin backup and forced writes off, timestamp update delayed
We have a Firebird database that's almost 200 Gbyte in sice, and for performance we have forced writes off. Please don't debate the risks of forced writes, we are aware of them. This is Firebird 3.0.4 ...
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336
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no performance improvement with pgpool query result caching
I'm trying to add query result caching to a PostGIS database that's frequently hit with the same (expensive) spatial queries. Looks like pgpool-II is currently the only well-developed solution.
...
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0
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543
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Service broker stuck infinitely looping using outdated activation stored procedure
I was debugging and stuck a bunch of log statements into my activation procedure including a statement that logs the value of @@ROWCOUNT that is used in this manner:
INSERT INTO ###Debug(SomeMessage, ...
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1
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33
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MySQL consumes memory for each portion of read
I'm using MySQL instance for read only operations (data migration to another DB).
I'm reading several dozens of millions rows from one table using limited portions of data (100 000 rows) using select ...
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0
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1
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59
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Caching results of query for part of table that almost never change
In our database we have a table with a very large number of rows. Let's call it Table1. The greatest difficulty for us is a COUNT query to this table with some conditions (see example below):
Query1
...
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