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. I was a bit perplexed by this issue, since the system was certainly no slouch — plenty of cores, 3TB of memory, and XtremIO storage. Change the Target Recovery Time of a Database.

C++ 58

C++ Database Servers Storage 58

Percona

JUNE 4, 2023

Before we dive into the differences between MariaDB and MySQL, we will provide a thorough examination of each relational database management system (RDBMS). While originally designed to be a drop-in replacement for MySQL, it evolved into its own distinct database management system and is now maintained and supported by the MariaDB Foundation.

Open Source 52

Open Source Servers Storage Scalability 52

Brendan Gregg

NOVEMBER 29, 2017

In this configuration, the AMI and boot is paravirt (PV), the kernel is making hypercalls instead of privileged instructions, and the system is using paravirt network and storage drivers. But not all workloads: some are network bound (proxies) and storage bound (databases). ## 5. The AMI and boot are now HVM. Impressive!

Virtualization 111

Virtualization AWS Hardware Storage 111

SQL Server According to Bob

DECEMBER 18, 2018

Durability: “In database systems , durability is the ACID property which guarantees transactions that have committed will survive permanently. Microsoft SQL Server Database Engine Input/Output Requirements. Device level flushing may have an impact on your I/O caching, read ahead or other behaviors of the storage system.

Servers 90

Servers Media Cache Storage 90

Alex Russell

MARCH 6, 2021

Back in 2016, I gave a talk outlining the causes and effects of the terrible performance of web apps built using popular tools on the fastest-growing device segment: low-end to mid-range Android phones. A then-representative $200USD device had 4-8 slow (in-order, low-cache) cores, ~2GiB of RAM, and relatively slow MLC NAND flash storage.

Performance 124

Performance Network Cache Metrics 124

SQL Performance

MAY 29, 2019

From SQL Server 2016 onward, FastLoadContext is enabled by default ; the trace flag is not required. For more background, see the Data Performance Loading Guide and the Tiger Team notes on the behaviour changes for SQL Server 2016. FastLoadContext can be disabled on SQL Server 2016 using documented trace flag 692. DEFAULT ''. )

Cache 64

Cache Testing Servers Code 64

Percona

JANUARY 17, 2019

now has a version which will support parallelism for SELECT queries (utilizing the read capacity of storage nodes underneath the Aurora cluster). Test data and versions. For my test, I need to choose: Aurora instance type and comparison. Aurora PQ works by doing a full table scan (parallel reads are done on the storage level).

Cache 45

Cache C++ AWS Airlines 45

SQL Performance

MAY 1, 2019

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. The following demo script should be run on a development instance in a new test database set to use the SIMPLE recovery model.

Servers 47

Servers Database Testing Performance 47

SQL Performance

APRIL 23, 2019

SQL Server 2016 introduced serial batch mode processing and aggregate pushdown. Columnstore storage. To understand this, it is necessary to first review how columnstore storage works at a high level: A compressed row group contains a column segment for each column. This is the basic test setup: USE Sandpit ; GO.

Servers 67

Servers Testing Metrics Storage 67

Brendan Gregg

NOVEMBER 28, 2017

In this configuration, the AMI and boot is paravirt (PV), the kernel is making hypercalls instead of privileged instructions, and the system is using paravirt network and storage drivers. But not all workloads: some are network bound (proxies) and storage bound (databases). ## 5. The AMI and boot are now HVM. Impressive!

Virtualization 40

Virtualization AWS Hardware Storage 40

SQL Performance

MAY 16, 2019

Both of the following tests must pass for SQL Server to choose to set DMLRequestSort to true when inserting to an empty clustered index with table locking specified: An estimate of more than 250 rows at the input side of the Clustered Index Insert operator; and. Test ; END ; GO. DMLRequestSort Conditions. DROP TABLE dbo. DEFAULT ''. )

Cache 67

Cache Servers Testing Storage 67

Particular Software

OCTOBER 3, 2017

This article was originally published on the NDC 2016 Blog. It's a place filled with unit tests, automated integration tests, and code written using the "most latest" framework in town. Because you're on the outside of the monolith, your database technology constraints also disappear.

Architecture 49

Architecture Database Code Systems 49

Alex Russell

APRIL 29, 2021

Thanks to the Web Platform Tests project and wpt.fyi , we have the makings of an answer for the first: Tests that fail only in a given browser. wpt.fyi 's new Compat 2021 dashboard narrows this full range of tests to a subset chosen to represent the most painful compatibility bugs : Stable-channel Compat 2021 results over time.

Media 145

Media Games Education Engineering 145