Questions tagged [storage]
For questions about the persistent storage of database data.
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20 views
How Blockchain Databases Work
I feel like I read somewhere back about blockchain databases but I can't seem to find anything too solid on the topic. This paper called Blockchain Databases doesn't offer much in terms of description....
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0answers
51 views
“Slow Storage Writes on Drive T” warning from sp_Blitz
We migrated our platform to new SQL Server 2016 instances a couple of nights ago. Immediately following the migration, we ran sp_Blitz again, but noticed the following entry, which relates to the ...
0
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2answers
51 views
Is there a disk space impact when choosing NULL vs empty array {} for the default of an ARRAY[] column? [duplicate]
My intuition is NULL will take up less space than {} when used as the default value of an ARRAY[] column in PostgreSQL.
Am I correct?
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0answers
47 views
IO Test for SQL Server
I was trying to use DiskSpd to check IO subsystem performance but one thing I was confused about is regarding the -T switch, which (according to the documentation) is the number of threads per file. ...
0
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3answers
34 views
Can I move / Modify the Object in Object Storage Service (OSS)
I am using Alibaba Cloud - ECS and have Storage Bucket - Object Storage Service (OSS).
File Storage structure is like
oss:/bucket/abc/xyz/123.jpg/
My Question is
Can I move or modify the objects ...
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0answers
30 views
How should I organize my physical storage on 5 ssd single server for 2.2 TB database
I need to migrate a 2.2 TB database to a better organized single server with 12 physical cores. New server has 5 SATA SSDs 1 TB each, will upgrade to 6 SSDs 1 TB each.
My current design is (this is ...
9
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2answers
155 views
Increased waits during checkpoint after upgrading to better storage
When we migrated from an older all flash array, to a newer all flash array (different, but well established vendor), we started seeing increased waits in SQL Sentry during checkpoints.
Version: ...
-3
votes
1answer
47 views
Can we shrink a 1.6 TB SQL Server DB in Simple mode with only 12 GB Storage left?
We saw your article about this topic and wondered if you can answer this question:
Can we shrink a 1.6 TB SQL Server DB in Simple mode with only 12 GB Storage left?
Here is your article that we saw:
...
3
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0answers
148 views
How Graph Databases Store Data on Disk
I have seen these papers:
TurboGraph
GraphChi
BiShard Parallel Processor
G-Store
NXgraph
GridGraph
...and a few others. I am new to databases (other than having used them for web apps without ...
2
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1answer
32 views
How to Store Trees on Disk
I am wondering how to store trees on a physical disk, for perhaps a tree-oriented database like an XML database.
Wikipedia states about XML databases:
...custom optimized data structures are used ...
1
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1answer
50 views
How Database Formats Files for Disk
This SO answer outlines how MySQL organizes its database into files, but doesn't describe the structure of the files themselves.
I am wondering, at the physical level, how relational database ...
7
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1answer
1k views
What are the current best practices concerning varchar sizing in SQL Server?
I'm trying to understand the best way to decide how big varchar columns should be, both from storage and performance perspectives.
Performance
From my research, it seems that varchar(max) should ...
3
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2answers
469 views
In what cases are BLOB and TEXT stored in-line on InnoDB?
I've googled this and can't find it, you can see Rick James mention it here.
... BLOB and TEXT are not always stored separately
The answer on What is the difference between MySQL VARCHAR and TEXT ...
0
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1answer
29 views
Shrinking the database partition if autogrow is turned off?
I want to know:
Are there chances of shrinking the database partition if autogrow is turned off?
Also, are there chances of data fragmentation and increase in seek times if we fully extend size ...
-3
votes
2answers
64 views
What are some real world applications that generate large numbers of records in a database every day and what are those metrics? [closed]
I'm trying to get some perspective in today's day and age what is considered a large amount of data or large number of records generated in a day and what real world applications are doing that. I ...
1
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2answers
38 views
How does the optimizer in Oracle Database use I/O statistics?
I would like to help Oracle's query optimizer make better-informed decisions. I have been unable to find much information on how the optimizer determines the cost of I/O operations, other than ...
16
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1answer
252 views
CREATE DATABASE on RAW partitions no longer works?
I'm attempting to create a database using two raw, i.e. unformatted, partitions.
Microsoft Docs states you can do this, you simply need to specify only the drive letter of the raw partition, as in:
...
3
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1answer
104 views
Tempdb size strategy
I've recently started my role as a DBA and my initial task has been to take ownership and redeploy a database provided by a 3rd party to help us conform to GDPR legislation.
As a consequence, I've ...
5
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4answers
861 views
Best way to store physical stock data in a SQL db
I work for a retail company and we are in the process of building a new data warehouse. One element we need to store is physical stock data as to how many units of any sku are available at a certain ...
1
vote
1answer
21 views
How can I find the stored binary value of a DOUBLE value in MySQL?
Given the following table, backed by MySQL 5.7/InnoDB:
CREATE TABLE mytable(mydouble DOUBLE) SELECT 0.005 `mydouble`;
how can I find what exactly InnoDB is storing on the disk for the value 0.005?
...
0
votes
1answer
30 views
Is it possible to allocate data free for certain table?
After deleted a large dataset (~50GB) and optimized tables, some tables have data free (~50GB) and parts of tables have only data free (~KB). As my understanding, the data free are reused and not ...
1
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1answer
174 views
Post Migration error in sql server error log
I am seeing below error messages when we have moved/migrated databases to new server/instances from SQL2K12 stanadlone to cluster
last target outstanding: 20800, avgWriteLatency 30
average throughput:...
0
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1answer
53 views
Storage provisioning for Microsoft SQL Server
I need help with my Microsft SQL Server file setup!
I have a TEST Microsoft SQL Server with 3 RAID1 (SSDs):
C: (240 GB) - O/S installed
L: (460 GB)
M: (900 GB)
I have a PROD Microssoft SQL Server ...
0
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0answers
27 views
Storing a lot of text / string data strategies - analysis and solution
I have a LOB application backed by SQL Server 2016.
Over the past few weeks, theres been issues whereby the SQL Server start throwing timeout errors - which has led to a bit more digging into the ...
2
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1answer
60 views
Durability of storage in second generation google cloud sql
How durable should I expect data for a Google Cloud SQL instance to be? Just a single instance, with the high-availability option disabled.
AWS explicitly mention that Amazon Aurora data is stored in ...
0
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0answers
28 views
Storage design for SQL Server 2014 VM
I have a 2 node HyperV 2012 R2 cluster sitting on top of shared JBOD storage. I am virtualizing A standalone deployment of SQL Server 2014 Standard on this platform.
To isolate and provide separation ...
1
vote
1answer
85 views
Optimizing column types for reduced overall database size
Given the following table:
CREATE TABLE avl_historico (
fecha timestamp with time zone NOT NULL,
latitud double precision DEFAULT 0 NOT NULL,
longitud double precision DEFAULT 0 NOT NULL,
...
1
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0answers
393 views
why SSD is slower than HDD SAS 15K on DBMS PostgreSQL?
Someone help me analyze the two execution plans below (Explain ANALYZE used), is the query 9 of TPC-H benchmark.
I'm using two servers HP Intel Xeon 2.8GHz/4-core - Memory 8GB. O.S. Debian8, using ...
1
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0answers
28 views
EMC Recoverpoint works for database?
As a solution for replication, to protect VM, LUNs and recovery including database, EMC Recoverpoint was presented by our vendor.
But in EMC paper's, the only one database related example ilustrates ...
2
votes
3answers
150 views
How to create a normalized database to manage inventory for a small business? [closed]
I am writing a Java application to manage the inventory of a small furniture business. I know little about databases, I have a bit of experience with SQL queries and more experience with Java ...
1
vote
3answers
192 views
SQL Server 2016 SP 1 on HP 3PAR environment causes weird head blocker
My client is on HP 3PAR hardware. Three servers are on different geographical locations, connected with a 40 gbit fibre connection. The SAN is SSD only, the machines have lots of cores.
The ETL ...
3
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1answer
256 views
Why is my database 12 times bigger than inserted data?
I have a short question concerning my database size. I need to insert data in a database. Before the insert, some calculations need to be done.
The point is: from 50 mb plain data (~700,000 lines), ...
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0answers
32 views
What does column family-oriented datastore mean in practice
I was reading this article about HBase. Within it, the storage format of HBase is described:
HBase is referred to as a column family-oriented data store. It’s also row-oriented: each row is indexed ...
2
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1answer
77 views
NTFS filesystem fragmentation & other influence vs database files
As probably everybody knows, NTFS has a flaw in design which causes fragmentation during filesystem usage. On the other side, MSSQL uses files as database storage method, and what is more, typical ...
1
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0answers
317 views
SQL TempDB PCI-E NVMe card - 4K or 64K
Our primary OLTP workload is tempdb heavy (both reads & writes) based on virtual_file_stats DMV, and based on SPs all of which heavily use #tmp tables.
The server has 400GB of memory, more than ...
1
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0answers
171 views
Why is SQL Server unable to access partitions stored on UNC paths?
I have a database with its primary file and log file stored locally. One table is split into 101 partitions which are stored on a Windows share on another server accessed by a UNC path. Each partition ...
1
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1answer
93 views
Is SQL Server's fill strategy the same for multi-file tempdb as multi-file (non-tempdb) filegroups?
Will tempdb I/O from a single query be split across multiple tempdb files? (assuming that tempdb is configured to use multiple files, of course!)
For non-tempdb databases, MDSN seems to say that yes, ...
1
vote
1answer
96 views
What does “volume” mean in MAX_IOPS_PER_VOLUME?
When setting MAX_IOPS_PER_VOLUME in a Resource Pool, what exactly does "volume" mean? Specifically, how many "volumes" would be the following cases:
Locally attached disk that's split into two ...
2
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1answer
69 views
How does combining columns save disk space?
I am creating a table in SQL server and inserting records. Three columns from this table are AAA int, AAB int and AAC int. If I merge AAB and AAC into one column Comb1 char(2), it consumes 20% less ...
1
vote
2answers
566 views
SQL Server Disk throughput slower than diskspd
This is a bit of a broad question but I am trying to understand a storage performance behavior with two of our servers.
I was following https://www.brentozar.com/archive/2015/09/getting-started-with-...
3
votes
2answers
873 views
How to reclaim the storage space used by a heap?
I have a table without a clustered index in SQL Server 2008R2 Standard with a lot of unused space, as shown in the following image:
How do I reclaim unused space from MyTable?
Said table is declared ...
8
votes
1answer
168 views
Can't SQL Server store NULLs in fixed-length columns?
I came across this statement in the official Oracle documentation:
In Microsoft SQL Server, only columns with variable-length data types
can store NULL values. When you create a column that ...
3
votes
3answers
261 views
Configuring physical storage for a Microsoft SQL Server installation
I'm configuring a Microsoft SQL Server installation which will use a SAN for storage. For SAN storage I have:
A small number of SSD disks
A larger number of 10K disks
My SAN supports storage ...
1
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0answers
34 views
Compute bytes count occupied by surviving cells of a table [closed]
Let there be a table that grows to 5MiB.
After being VACUUMed let there be about 2MiB worth of DELETEd rows that is available for data in that table before starting storage claims to the operating ...
2
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1answer
2k views
Storing PLC Data in SQL Server database
I'm developing a software solution that requires storing raw data points originating from many PLCs (programmable logic controller, used to control industrial machines such as conveyor belts and ...
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0answers
33 views
How to use container to do database high availability?
About traditional database high availability, the method is like:
master-master replication
master-slave replication
automatic failover
If use container to do that, we can use these ways:
Use ...
0
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1answer
304 views
What is an efficient storage method to store Graph Data from GraphX (Spark)?
I generate graph data using Spark's GraphX library and I need an efficient way to store graph data. I have access to Apache Cassandra and ideally I want to store the graph data in there but the issue ...
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0answers
52 views
What parameters should I use to measure storage I/O capabilities
I want to measure the throughput of my disk subsystem using: https://gallery.technet.microsoft.com/DiskSpd-a-robust-storage-6cd2f223
what parameters should I use to closely emulate SQL I/O?
Is there ...
0
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0answers
102 views
Decent benchmark performance, poor real world
We recently deployed a new SQL box, running SQL Server 2016 on Server 2012 R2.
I'd read good things about the new version of Storage Spaces and had a chance to benchmark it against the H310 raid card ...
1
vote
0answers
130 views
Why ndb data memory is 94% if i m using disk storage cluster
I have following structure
2 data node
1 management node
2 sql node
i have create one log file of initial size 200M
then created table space and added 3 data file
data1.dat (initial size: 10GB)
...
