SQL Performance

FEBRUARY 1, 2022

This is done to make managing operations in the transaction log easier for the log manager in SQL Server. You can’t specify how many VLFs are created by SQL Server when the database is first created or the log file automatically grows, but you can influence it.

Architecture 53

Architecture Servers Virtualization Database 53

Percona

AUGUST 18, 2023

Why do you need multiple instances on the same server? Why not just create another database on the same instance? You can have a host with two or three instances configured as a delayed replica of the source server with SQL Delay of, let’s say, 24hr, 12hr, and 6/3hrs. ln -s /usr/local/Percona-Server-8.0.19-10-Linux.x86_64.ssl101/

Programming 82

Programming Servers Database Hardware 82

SQL Server According to Bob

JUNE 3, 2016

SQL Server 2016 changes the internal design to (CheckScanner), applying no lock semantics and a design similar to those used with In-Memory Optimized (Hekaton) objects, allowing DBCC operations to scale far better than previous releases. The following chart shows the same 1TB database testing. SQL Server. SQL Server 2014.

Hardware 40

Hardware Cache Servers Software Engineering 40

SQL Performance

JULY 16, 2019

A close monitoring of the hardware enthusiast community, including many of the most respected hardware analysts and reviewers paints an even more dire picture about Intel in the server processor space. Despite all of this, Intel is not going to lose their entire server processor business any time soon. So, what has changed my mind?

Servers 46

Servers Hardware Architecture Retail 46

SQL Performance

NOVEMBER 1, 2019

As I embark on my first PASS Summit in a few years, it is hard to contain my excitement about the newest version of SQL Server. As you may recall, back in SQL Server 2016 SP1, they opened up all of the programming surface features to all editions, and many (but certainly not all) of the performance and availability features.

Servers 40

Servers Hardware Database Availability 40

SQL Performance

JUNE 5, 2019

One of the more perplexing problems to troubleshoot in SQL Server can be those related to memory grants. Some queries need more memory than others to execute, based on what operations need to be performed (e.g. ALTER DATABASE [ WideWorldImporters ] SET QUERY_STORE = ON ; GO. sort, hash). USE [ master ] ; GO.

Servers 41

Servers Cache Database Metrics 41

Alex Podelko

OCTOBER 20, 2016

I am looking forward to share my thoughts on ‘Reinventing Performance Testing’ at the imPACt performance and capacity conference by CMG held on November 7-10, 2016 in La Jolla, CA. Cloud seriously impacts system architectures that has a lot of performance-related consequences. – Cloud. – Agile.

Performance Testing 100

Performance Testing Architecture Testing Performance 100

SQL Performance

MARCH 20, 2020

We're mid-cycle between releases, where we're not yet hearing about any of the features planned for SQL Server vNext. In SQL Server 2016, STRING_SPLIT solved a long-missing gap in a language that, admittedly, was not intended for complicated string processing. And that is what I want to bring up today.

Database 109

Database Servers C++ AWS 109

SQL Performance

JULY 27, 2021

Continuing my series of articles on latches, this time I’m going to discuss the DBCC_OBJECT_METADATA latch and show how it can be a major bottleneck for consistency checks prior to SQL Server 2016 under certain circumstances. But remember, this bottleneck only happens for versions of SQL Server earlier than SQL Server 2016.

C++ 54

C++ Servers Database Code 54

SQL Server According to Bob

DECEMBER 18, 2018

SQL Server relies on Forced-Unit-Access (Fua) I/O subsystem capabilities to provide data durability, detailed in the following documents: SQL Server 2000 I/O Basic and SQL Server I/O Basics, Chapter 2. Be sure to deploy SQL Server 2017 CU6 or newer for best data durability and performance results. “.

Servers 90

Servers Media Cache Storage 90

Percona

SEPTEMBER 19, 2023

This type of backup is suitable for large, important databases that need to be recovered quickly when problems occur. Physical backups are the backups that consist of raw copies of the directories and files that store database contents. 29 will let you set up redo log directory while performing a backup. Type 'help' or '?'

C++ 102

C++ Servers Storage Speed 102

Percona

FEBRUARY 2, 2023

Recall that logical replication works by using the PUB/SUB mode, where individual tables are published and are then subscribed by remotely connected databases/tables. The only real limitation is that one can only publish tables from a read-write server such as the PRIMARY. DML operations, such as INSERT, UPDATE, DELETE, TRUNCATE, etc.,

Games 87

Games Open Source Tuning Speed 87

SQL Performance

MAY 1, 2020

In a recent tip , I described a scenario where a SQL Server 2016 instance seemed to be struggling with checkpoint times. Still, if you stack a bunch of high-transaction databases on there, checkpoint processing can get pretty sluggish. A SQL Server DBA myth a day: (15/30) checkpoint only writes pages from committed transactions.

C++ 58

C++ Database Servers Storage 58

Percona

JANUARY 24, 2023

Some of the built-in features ( wal_compression ) have been there since 2016, and almost all backup tools do the WAL compression before taking it to the backup repository. Such “torn pages” are corruptions from the database point of view. But this comes with a considerable performance implication.

Database 115

Database Benchmarking Open Source Latency 115

Percona

APRIL 12, 2023

Whereas many open source software offerings — like the community version of MySQL — use the GNU General Public License ( GPL ), MongoDB has been under the GNU Affero General Public License ( AGPL ) and more recently under the Server Side Public License ( SSPL ), introduced by MongoDB itself. ” Nothing nefarious there.

Open Source 79

Open Source Programming Database Servers 79

Percona

JUNE 4, 2023

In this blog, we’ll provide a comparison between MariaDB vs. MySQL (including Percona Server for MySQL ). Introduction: MariaDB vs. MySQL The goal of this blog post is to evaluate, at a higher level, MariaDB vs. MySQL vs. Percona Server for MySQL side-by-side to better inform the decision making process. What is MariaDB?

Open Source 52

Open Source Servers Storage Scalability 52

SQL Performance

JUNE 22, 2021

The FGCB_ADD_REMOVE latch protects a data structure called an FGCB, or File Group Control Block, and there will be one of these latches for each online filegroup of each online database in a SQL Server instance. When the thread performing the file growth is done, it releases the latch and grants it to the first waiting thread.

Servers 54

Servers Database Code Performance 54

SQL Performance

OCTOBER 14, 2020

In my examples I’ll continue using the sample databases TSQLV5 and PerformanceV5. The issue is that even though SQL Server does support a short circuit concept at the physical processing level, there’s no assurance that it will evaluate the filter predicates in written order from left to right. Substitution/unnesting.

C++ 52

C++ Servers Code Efficiency 52

Alex Russell

MAY 9, 2022

Despite advances in browser tooling , automated evaluation , lab tools , guidance , and runtimes , however, teams struggle to deliver even decent performance with today's popular frameworks. What is Performance? It may seem a silly question, but what is performance, exactly?

Performance 86

Performance Latency Metrics Engineering 86

SQL Server According to Bob

JULY 13, 2016

20+ years ago when I joined Microsoft I was handed a diskette (maybe it was two), and was told “Here is SQL Server. So I proceeded to install SQL Server 4.20 There was a GUI as part of setup but within just a few clicks, SQL Server was installed and ready for use. So now there are more choices to make when installing SQL Server.

Servers 40

Servers Media Engineering Virtualization 40

SQL Server According to Bob

NOVEMBER 8, 2016

SQL Server 2016 Service Pack 1 (all SKUs) , in combination with Windows Server 2016 (All SKUs) or Windows 10 Client introduces non-volatile memory support for the tail of the log file (LDF) which can significantly increase transaction throughput. Create / Alter Database … LOG ON. NVDIMM is measured in nanoseconds.

Cache 40

Cache Servers Media Storage 40

SQL Server According to Bob

JANUARY 26, 2017

My goal is to resolve mysteries about SQL Server I encounter but do this without going straight the source code first. The first case that helped me start this journey was asked by a MVP within the SQL Server community (his first name starts with Joey<g>). That is to ensure your database is encrypted at the file level.

Servers 40

Servers Database Azure Cache 40

SQL Performance

DECEMBER 9, 2020

I’ll present the performance tests that I’ve done with my solution. What’s the best performing solution that you can conjure? You can create supporting tables in the user database if needed. Let’s proceed to performance testing. Testing different base table cardinalities is just one dimension to try.

C++ 114

C++ Servers Testing Processing 114

SQL Performance

AUGUST 14, 2019

In my examples I'll use a sample database called TSQLV5. You can find the script that creates and populates this database here , and its ER diagram here. GetNums ( 1 , @rows_per_partition ) AS RPP ; Our pitfall has both a logical side to it with a potential logical bug as well as a performance side with a performance penalty.

Best Practices 108

Best Practices Servers Database Azure 108

Percona

JANUARY 14, 2019

What if we use ClickHouse (which is a columnar analytical database) as our main datastore? Well, typically, an analytical database is not a replacement for a transactional or key/value datastore. Although such databases can be very efficient with counts and averages, some queries will be slow or simply non existent. Text search.

Database 40

Database Analytics Blockchain Healthcare 40

SQL Server According to Bob

JULY 12, 2016

Trace flags 2562 and 2549 are documented in knowledgebase article: [link] and the blog post [link] highlights the SQL 2016 DBCC performance improvements. For SQL Server 2008, 2012 and 2014 the trace flag behavior remains the same. Trace flag 2549 is used to change how DBCC sees the volume layout of the database.

Servers 40

Servers Design Engineering Database 40

Smashing Magazine

JANUARY 15, 2019

How Improving Website Performance Can Help Save The Planet. How Improving Website Performance Can Help Save The Planet. The Green Web Foundation maintains an ever-growing database of web hosts who are either wholly powered by renewable energy or are at least committed to being carbon neutral. Jack Lenox.

Website Performance 73

Website Performance Website Energy Performance 73

SQL Performance

MAY 1, 2019

This is reflected in the summary tables included in the Data Loading Performance Guide and the Tiger Team post. The summary rows for heap tables without indexes are the same in both documents (no changes for SQL Server 2016): An explicit TABLOCK hint is not the only way to meet the requirement for table-level locking.

Servers 47

Servers Database Testing Performance 47

SQL Performance

JULY 1, 2019

The results are technically non-deterministic since SQL Server could validly return any one of the rows in each group. Nevertheless, if you run this query yourself, you are quite likely to see the same result I do: The execution plan depends on the version of SQL Server used, and does not depend on database compatibility level.

C++ 58

C++ Servers Database Performance 58

SQL Performance

FEBRUARY 22, 2021

I would like to share a couple of recent examples that help illustrate how using deprecated SQL Server features continues to bite us. The system table sys.sysprocesses was replaced way back in SQL Server 2005 by a set of dynamic management views (DMVs), most notably sys.dm_exec_requests , sys.dm_exec_sessions , and sys.dm_exec_connections.

Latency 57

Latency Servers Monitoring Systems 57

SQL Performance

OCTOBER 29, 2019

There are multiple methods to look at poorly performing queries in SQL Server, notably Query Store, Extended Events, and dynamic management views (DMVs). Extended Events provides data about the individual execution of queries, while Query Store and the DMVs aggregate performance data. Each option has pros and cons. ORDER BY qs.

C++ 74

C++ Database Servers Tuning 74

SQL Performance

SEPTEMBER 2, 2021

A lot of things change over the course of a few major versions of our favorite database platform. SQL Server 2016 brought us STRING_SPLIT , a native function that eliminates the need for many of the custom solutions we’ve needed before. STRING_SPLIT() in SQL Server 2016 : Follow-Up #1.

C++ 59

C++ Servers Testing Database 59

SQL Performance

JUNE 9, 2021

That is, ones that are created as an object in the database, and stay there permanently unless dropped. In my examples I’ll use a sample database called TSQLV5. A table could be a base table defined as an object in the database, or it could be a table returned by an expression—more specifically, a table expression.

Database 140

Database Code Design Development 140

Percona

JANUARY 17, 2019

In this article, we will look at how this can improve the reporting/analytical query performance in MySQL. I will compare AWS Aurora with MySQL (Percona Server) 5.6 84.1 | | version_comment | Percona Server (GPL), Release 84.1, Result: ~10x performance gain, no index used.

Cache 46

Cache C++ AWS Airlines 46

SQL Performance

DECEMBER 9, 2020

I’ll present the performance tests that I’ve done with my solution. What’s the best performing solution that you can conjure? You can create supporting tables in the user database if needed. Let’s proceed to performance testing. Testing different base table cardinalities is just one dimension to try.

C++ 61

C++ Servers Testing Processing 61

SQL Server According to Bob

JANUARY 28, 2018

Resource Manager – Database, File System, with ACID capabilities. Note: SQL Server can be a client using a linked server, allowing SQL Server to become an APP and/or an RM ). DtcGetTransactionManager contacts the host, performing a remote registry access to determine the connection and proxy information.

Servers 40

Servers Azure Engineering Java 40

SQL Performance

APRIL 8, 2019

These AMD EPYC processors have a number of advantages for SQL Server workloads, as I will explain in this article. This 14nm first-generation AMD EPYC 7551 processor has 32 cores and 64 threads, and it works in one or two-socket servers. Both of these Intel processors are special bespoke models that are not in the Intel ARK database.

Azure 42

Azure Virtualization Storage Benchmarking 42