The Importance of Query Optimization in SQL Server Plus Tips

query optimization in SQL Server

The database is a vital part of a majority of IT systems as it contains that data that needs to be processed for utilization. SQL is the standard language for fetching data from the database using queries and query optimization in SQL Server helps maintain database performance.

The queries used to communicate with the database are almost always simple and quick. The most common operations include the four major data manipulation techniques (create, select, update, and delete) that execute at quick rates in most cases. However, as you already know, they aren’t the only tasks an administrator has to do in a database.

Why Experts Recommend Query Optimization in SQL

Operational databases may have a requirement to execute statements that take a long time. For instance, queries that need access to several tables or include tasks such as aggregation.

Although statements that operate on data warehouses aren’t time-critical, the ones running on operational databases are. They are necessary to fetch the requested information as quickly as possible – which makes SQL Server performance tuning important. One of the best examples of systems that need optimal SQL is one that has access to a geo server. A geo server contains millions of geographical information spread across countless tables.

Moreover, the database operations taking place on this data is often performance heavy. Such tasks may include the intersection of lands and calculations of area, the distance between two geographical locations, etc.

These involve complex geo operations that need a large amount of data present in multiple tables. If the SQL statement used for these operations isn’t efficient, it could take days or months to fetch the results. This is where the DBA will need query optimization in SQL Server to ensure the users don’t have to wait too long to get a result.

Some Quick Tips for Maintaining Optimal Database Query Performance

Take a look at some time-tested techniques of optimizing queries in SQL that not only save a lot of time and resources but are also useful for a wide range of databases:

  • Check efficiency using LIMIT – Many times, the queries have to run on a huge scale of data. You would not want to wait for your statement to execute completely before finding out that you have used the wrong statement or it was inefficient. Therefore, limiting your statement to a smaller amount of information can help you check its validity and with SQL Server performance tuning. Once you’ve run the query and are satisfied with its efficiency, you can carry it out on the scale you want.
  • Long statements can help – At times, you may have written statements that may seem simple to you as they didn’t take long to understand. However, they took too long to actually execute. In databases involving time-critical operations, the opposite would be preferable. Even though the queries will become complex and take a bit longer to understand, they will save a lot of time.
  • Give preference to quicker data structures – This depends on the programming-based knowledge of the DBA. For example, integer comparisons are far quicker than string comparisons.
  • Don’t be tempted to use IN operator – Checking the existence of certain data in a table may be important. But try not to use the IN operator as it slows down the result.

In Conclusion

As mentioned before, these tips are useful for a majority of databases out there. Since SQL is a declarative language, certain databases are likely to optimize for the cases we have talked about above.

However, test the tips before you try to apply them for query optimization in your database. In case some of these don’t work, you may want to consider using a tuning tool to make things easier. Get in touch with us to know how our tuning tool can simplify database query optimization for you.

Importance of Backup & Recovery in MySQL Database and SQL

MySQL database and SQL

A database is the cornerstone of any application. For this reason, maintaining one or more backup and recovery options remains a priority for every database professional. There are multiple alternatives you can choose from as per the specific needs of your organization’s database.

In this post, we will examine some of the most popular back-ups and restore strategies for MySQL database and SQL. We will also touch upon the reasons why databases require backups on a regular basis.

Why Do We Need Backups for MySQL Database?

As a DBA, you’ll need backup and recovery to support data in multiple cases, such as:

Discrepancies in Data: Users may accidentally delete or update incorrect data in the primary or replica node.

Data Centre Failure: An indefinite power outage or internet connectivity issue can spell trouble for your organization.

Disk Damage: If the disk is stalling for too long due to some kind of damage, it can greatly reduce performance. In cloud services for Oracle database, it translates into a broken DB instance that cuts access.

Broken Data: In case of a power outage, MySQL may fails to write data and close files as usual. There are also instances where MySQL fails to restart and doesn’t work despite the crash recovery process because of corruption in data.

Legislation/Regulation: Backups and recovery options ensure business value and client satisfaction.

Various Kinds of Backups for MySQL Database

Given below are some common backup categories that suit a range of needs:

Physical: These comprise the exact copies of database files and may contain part or all of the MySQL directory. The most common use of this type of backup is to make a new replica node and respond to host failure in a convenient manner. Experts recommend restoring data with the help of the same MySQL database version.

Offsite: This is one of the most recommended backup alternatives as it guarantees an untouched copy in case of data centre or host failure. It involves copying the data to the cloud, an external file server or another external source. However, sometimes it may take longer to download the files from the cloud or server than the recovery process. Therefore, experienced database professionals keep about a week of data locally on a backup server for quick recovery.

Logical: It is useful for smaller quantities of data as it is slower in comparison to physical backup methods. It essentially consists of dumps from INSERT and CREATE statements. It is useful in addressing data corruption or when you must recover a subset of tables. Although the output is greater in logical backups, especially when that data is present in text format, you can perform a quick compression if the software you’re using requires it. For instance, you can use Mydumper and mysqldump to compress and redirect the data to the zip folder.

Incremental: This type of backup contains all the changes made in the organization’s Oracle database and SQL server since the last backup. It is, therefore, quite useful for enormous datasets since it allows you to take small backups (experts recommend this after you’ve taken a full backup) as data comes later.

Differential: It consists of copying the modifications since your previous backup. One advantage of a differential backup is that it saves disk space. This is because the data in these backups mostly remains the same, so the result leads to backups that are substantially smaller in size.

Make Your Oracle Database Work Faster with these 6 Methods

improve performance of sql query

Every Oracle database admin dreads the day when they receive a flurry of complaint calls from users regarding slow online performance.

That’s why, if you’re responsible for managing database performance in your organization, you’ll want to ensure this doesn’t happen. How? By preparing your infrastructure to handle increased loads. Supporting it with performance tuning is also essential, especially when the systems slow down or become entirely unresponsive.

In this post, we’ll consider six important (yet often overlooked) methods and tips to improve Oracle database performance. These will also help you gain the most from your efforts and make sure your environment stays fully operational.

6 Ways to Optimize the Performance of Your Oracle Database

Take a look at the following tricks and tactics to improve Oracle database performance, explained in a simple manner: 

1. Maintain Optimum CPU Utilization Levels

It may be necessary to carry out manual tuning processes if, for some reason, you cannot apply the automatic diagnostic features Oracle provides. For this, you must make sure of complete CPU utilization in the user space. Check it to determine whether any non-database tasks are taking up CPU and restricting shared CPU resources.

2. Have a Firm Grasp of System Capabilities

Understanding the importance of baselines is essential to improve performance of SQL query. It helps to preserve a set performance baseline that you can refer to in case of performance issues.

You can do this by keeping an eye out for peak usage periods while measuring current performance. This will enable you to manage bottlenecks easily.

3. Make Use of an AWR (Automatic Workload Repository) Tool

An AWR is extremely useful as it gathers, processes, and maintains performance stats. It also provides a clear picture of your database’s health. The Automatic Database Diagnostic Monitor (ADDM) can help you gain actionable insights from the information you gain here. Together, these tools will save you time and money while enhancing the performance tuning process.

4. Tune Inefficient SQLs Using the Right Tools

The quickest and the least risky way to get rid of Oracle database problems is to tune the SQL using the right query plan. You can also use tuning tools for the Oracle database, such as those provided by Tosska Technologies Limited.

Tosska’s SQL Tuning Expert (TSE™) for Oracle® is ideal for all levels of experience and expertise. Its professional version, Tosska SQL Tuning Expert Pro (TSE Pro™) for Oracle®, can improve performance of SQL query with or without source code. However, these tools work best when you define and measure system issues correctly first.

5. Boost Storage Efficiency

It is possible to improve database performance by enhancing the performance of the storage platform. Review the existing storage for your Oracle database server and see if you can opt for alternatives.

For instance, flash technology offers considerably greater bandwidth and decreased latency to IO-bound workloads. It allows targeted provisioning, thereby boosting performance while eliminating the need to refresh the whole database. The key is to use flash storage for database objects that will benefit the most, leaving the rest in traditional storage.

6. Opt for a Dedicated Database Infrastructure

Sometimes, a common infrastructure platform can be the reason behind reduced performance results. No amount of tuning efforts proves sufficient in such cases. One of the most effective solutions is to provide a dedicated infrastructure to the database. This helps stabilize performance for database workloads and convenient management as well as effective monitoring and security. 

Ready to improve Oracle database performance in the simple ways mentioned above? You may choose to seek assistance from Tosska’s professional tuning tools for Oracle. They are designed to help you get the most out of your database and maintain a fully operational environment.

SQL Performance Tuning: 5 Things to Do for Faster Results

query tuning in sql

Is your SQL Server falling behind in terms of performance? Are poorly-written queries slowing down your applications? Before you set out in search of professional help, make sure you’ve tried everything you could to resolve the issues you’re facing on your database. 

Many problems related to SQL Server can be handled easily with preventative maintenance, patches, and a few activities performed on a regular basis. You can always depend on our SQL performance tuning tools if nothing works for a particular situation. But before that, read the five important things you can do to fix database performance.

5 Things to Do for Effective SQL Performance Tuning

Given below are five simple things you can do to improve database performance:

Check if your SQL Server is up-to-date

An older query engine out of active development is bound to get you in performance-related trouble every now and then. Moreover, the newer versions have much better diagnostic support and will make things faster in multiple ways.

For starters, they come with new versions of the query optimizer. Although Microsoft provides a few tweaks here and there in its service packs, major version releases contain all the best improvements. Other advantages include:

  • Bug fixes
  • New CPU instruction sets
  • Latest software development techniques

Even a 32-bit to 64-bit upgrade can go a long way in improving database performance. This will help regardless of whether you are performing SQL tuning for Oracle or SQL Server.

Increase the Memory

Maxing out its memory will make a difference in its performance. This is because the database utilizes it to cache data instead of making additional trips to disk. Additionally, you gain more memory for cache query plans and can use it for larger sorts and joins. Another advantage is a potential decrease in disk and CPU utilisation, which further helps with SQL performance tuning. Just remember to raise the memory configuration in your SQL Server so it actually makes use of the new RAM.

Open Task Manager

If things remain slow after you’ve increased memory and upgraded your SQL Server,  it’s time to open Task Manager. Sort by CPU, followed by memory, and close any running apps, processes, or software that’s eating up space and you’re unaware of. Configure exceptions for antivirus software, if you have anything installed.

Windows may also be caching data for file system access, stealing RAM from server-side apps such as SQL Server. This can be checked by looking at the Cached number in the “Physical Memory (MB)” tab.

Check the Event Log

This includes both – the Windows Event Log and the SQL Server Log – as they both have potentially useful information. In case Windows or SQL Server are facing any sort of issue, these logs will certainly have more details about it.

You’ll know whether SQL Server is lagging due to hardware-related problems, facing long disk wait times, or dumping core. There may be other services with issues on the server that you can find out about here.

You can also read our post on SQL tuning for Oracle for some useful tips.

See if SQL Server alerts are set up

It is important to ensure these alerts are configured. They will, in turn, help you make sure you’re updated on everything that’s happening in SQL Server. As the person in charge of the database, you need to be aware in case the storage is falling short or other serious errors in SQL Server.

SQL Query Performance Tuning: A Look at Various Plan Formats

SQL query performance tuning

Database professionals are often familiar with the fundamental maintenance tasks for SQL Server. However, they may have to perform the optimization of SQL queries and keep an eye on query plans from time to time.

This may lead to confusion as to which type of query plan they should use. Here, we will cover the different types and formats of query plans and how to obtain them for SQL query performance tuning.

Query Plan Types and Formats for Efficient SQL Query Performance Tuning

To start with, there are two major kinds of query plans: the estimated and the actual execution plan. Users can obtain these in three distinct formats – text, graphical, and XML.

Keep in mind that users who wish to create these execution plans will require SHOWPLAN permission first. This is also true in the case of query plans and SQL tuning for Oracle.

Text-Based Query Plans

This type of plan can be procured using one of the three methods given below:

  • Set SHOWPLAN_Text – The query will not be run by SQL Server, but this method should fetch information about the manner in which queries run. In short, this statement will display information regarding the Estimated Execution plan.
  • Set SHOWPLAN_All – Again, SQL Server won’t run the query but it will fetch thorough details regarding query execution, i.e the way it executes them and which resources it uses for this purpose. You can also get more details about the Estimated Execution plan.
  • Set Statistics Profile – SQL Server will run the statement and display comprehensive data regarding query execution. This information includes the precise number of rows that were actually processed and all the resources that have been utilised for executing these queries. This command will also fetch details regarding the Actual Execution plan.

Graphical Query Plans

This format allows users a look at numerous sources of information and plenty of tooltips in SQL Server Management Studio.

Note that if you want to view the Estimated Execution Plan, you can do so once you press Ctrl+L in the query window. To view the Actual Execution Plan in the same results set, press Ctrl+M.

XML Based Query Plans

This type of query plan gives the most comprehensive details of the plan in the extremely portable XML format. You can obtain query plans in this format using two methods:

  • Set SHOWPLAN_XML – The query doesn’t run but returns detailed information about how the statements execute and the resources used for the query execution. SQL Server also displays a detailed XML document that has the Estimated Execution plan.
  • Set Statistics XML – SQL Server runs the statement and shows information regarding query execution in exhaustive detail. This includes information on the actual number of rows processed as well as the resources applied in the query execution. It fetches a properly created XML document consisting of the Actual Execution plan, helping in SQL query performance tuning.

How these Query Plan Formats Differ in Use

The graphical format is usually the simplest to read which is why beginners usually start with them. The best way to read graphical query plans is from right to left moving upwards from the bottom while following the arrows. Additionally, you can make things easier with the Zoom In and Zoom Out functions.

You can view further details from Graphical plans with the help of ToolTips. All you have to do is point your cursor at the icon you want to know more about. While this is an extremely useful feature, it can get complicated to view every detail on a complex query with the help of this tool.

This format also forms the link between the Text and the XML formats. This is because you can save Graphical Plans in XML format. If you’re trying to perform SQL tuning for Oracle, you may consider a SQL tuning tool depending on your requirements.

Text plans, on the other hand, are more difficult to read and lack simpler rules to understand them. However, they prove useful for those who have experience with execution plans and know what and how to look for.

Optimization of SQL Queries: Database Engine Tuning Advisor

optimization of SQL queries

If there is one complaint business users may have about their production database, it is slow performance. Database professionals, therefore, often try to focus strictly on finding out and resolving the source of the issue in the database.

The Database Engine Tuning Advisor (DTA) is one of the best tools in this regard. It helps DBAs analyze workloads and uncover areas that can be improved. In this blog, we will discuss the working of this tool along with a few additional details.

What is the Database Engine Tuning Advisor?

It is a tool that assists with the optimization of SQL queries and was introduced in SQL Server 2005. Before it, SQL Server had a feature known as the Index Tuning Wizard.

The DTA is designed to assess a workload and provide recommendations to boost query performance. Some of its suggestions include:

  • Making partitions
  • Incorporating indexes
  • Adding statistics (this helps resolve the issue of automatic statistics not getting created despite the auto_create_statistics option being ON)

Apart from locating every type of potential for enhancement, the Oracle Database Engine Tuning Advisor will build a T-SQL script for users to execute in order to carry out the recommendations made by it.

How to Launch the DTA for the Optimization of SQL Queries

You can commence its use through multiple methods:

  • Open the Start menu, scroll to the SQL Server application group and look for the Performance Tools folder.
  • If you’re using the SQL Server Management Studio application, you can select the tool from the Tools menu.
  • The SQL Server Profiler also has this tool in its Tools menu.
  • You can find it with the select analyze query in DTA on the SQL Server Management Studio Query menu. This also enables you to pass a T-SQL section to the tool for analysis.
  • Open the Command Prompt, type “DTA -?” for a glimpse at the available alternatives.

Normally, you can create a workload by collecting multiple statements in a file or with the help of the SQL Server Profiler. An important point to bear in mind is that the workload being sent to the Advisor for evaluation needs to be representative of the average workload.

What the Database Engine Tuning Advisor Does

The Database Engine Tuning Advisor makes recommendations on the basis of the workload you send for analysis. Therefore, a limited workload will result in inadequate recommendations. The best thing to do is to collect the workload through the Profiler, save the results in a text file, and send the trace to the Advisor.

The SQL Server Profiler plays an important role in the optimization of SQL queries. It can be launched from its location in the SQL Server application folder (in the Start menu) or among the list of tools in the SQL Server Management Studio.

In case you want to know the properties of the new trace, follow these steps –

  • Click on the dropdown list in the dropdown menu of the tool window (for the trace template) and select Tuning. The trace template gathers the events considered necessary by DTA.
  • Select the ‘Save to file’ and type in the file name you want before passing it to the Database Engine Tuning Advisor once the trace is complete.

Selecting a SQL Server Database Version for Your Company

SQL Server database and SQL

Choosing the right version of SQL Server is important for the performance you desire. If you’re installing an older one because your organization’s management prefers an older build or the vendor is unable to support newer versions, it is important to let them know which version your company needs, and why.

For this reason, we will discuss some popular versions of SQL Server from older to newer and mention their advantages in this blog.

Which SQL Server Version Works Best with SQL Performance Tuning?

Knowing the versions that support this task is extremely important because it will give you the ability to improve the SQL Server database and SQL performance.

To that effect, we will discuss the SQL Server 2016, 2017, and 2019 versions here.

SQL Server 2016

This version was chosen by a lot of independent software vendors or ISVs for one reason – 2016’s Service Pack 1 edition came with Enterprise features in Standard mode. These helped create a single application version that worked simultaneously for both Standard as well as Enterprise clients.

Advantages of Choosing this Version:

  • It is easy to find support material online as this version is quite popular and numerous database professionals are well-versed with this version’s tools.
  • Standard Edition users may find this version appealing since it supports 128GB RAM and additional space for internal functions such as query plans.
  • Support for this version ends after 2026 – longer than the older versions (2012/2014).
  • Newer applications that have additional compliance requirements will benefit from features in this version such as Always Encrypted, temporal tables, and Dynamic Data Masking. These will make it somewhat easier to protect and monitor sensitive information.
  • You can have both row store and column store indexes in this version, unlike the earlier ones that only had row store indexes.
  • If you need query plan monitoring to help with SQL performance tuning, you can use the Query Store’s features provided in SQL Server 2016 for this purpose.

SQL Server 2017

Being a newer release, it is one of the most regularly updated versions with patches coming in almost every other month. These patches are important because they resolve significant problems. It also comes with a minimum commit replica configuration to ensure commits are accepted by several replicas.

Advantages of Choosing this Version:

  • The upgrades are easier to get from this version onward due to a Distributed Availability Group that contains multiple SQL Server versions in it. Before this, we had AG version upgrades that were not as convenient, leading most users to construct a new cluster and migrate to it rather than opt for an upgrade.
  • This version contains batch mode execution plans, which gives those who require high-performance column store statements an advantage.
  • If you must run your SQL Server on Linux, you may consider SQL Server 2017 as several bugs have been resolved in the Cumulative Updates.
  • It’s a newer version so support will last longer than that of its predecessor.

SQL Server 2019

Released on November 4, 2019, this version is the latest in the SQL Server series. Naturally, it comes with the longest support lifespan, i.e. it will be supported until 2030. This version also receives regular patch updates to fix many significant issues in the form of Cumulative Updates.

Changes and Features in this Version:

  • Patch contents aren’t documented anymore. Moreover, you are likely to receive updates with undocumented new features – something to consider in case you require it for mission-critical production environments.
  • There is a bit of a learning curve thanks to some cutting-edge features in this version, so be prepared to perform some experimentation as you learn.
  • Some of the best performance features are included in the 2019 compatibility mode. However, you will have to keep a close eye on all SQL Server databases and SQL queries – even the ones running fast at present – as these will alter your current execution plans. In other words, you will have to test both slow and fast queries to make sure the slow ones speed up and the fast ones don’t fall behind in performance.
  • Table variables have gotten better in this version along with user-defined functions.
  • Additional features to watch out for including Big Data Clusters, Java support, and high container availability, so you may want to explore this version if you’re looking for perks like these in the SQL Server you want.

In Conclusion

At this point, SQL Server 2017 might seem like the best version to go with, thanks to a balance of features, stability, and support lifespan. Furthermore, you’ll receive plenty of help with SQL performance tuning – a lifesaver for overworked professionals who may not have the time or resources to upgrade every server every year.

5 Essential Paid & Free SQL Tools for Windows SQL Database

MySQL database and SQL

Effective database management requires one or more tools regardless of the platform your databases run on. The benefit of these tools is, whether they are operating on Windows, macOS, Linux, or the cloud, the tools mentioned below don’t require the same platform as the databases. 

Thanks to plenty of choices when it comes to SQL management tools, it may seem difficult to select the ones that will work best as per your specific needs. In this blog, we’ve picked out the best paid and free SQL tools for Windows along with their essential features.

Free SQL Tools for Windows with a Graphical User Interface (GUI)

Consider the following free SQL tools for Windows to help you with efficient database management:

  1. SQL Server Data Tools (SSDT)

The SSDT is designed for a variety of databases such as Azure SQL, SQL Server relational databases, RS reports(Reporting Services), IS packages(Integration Services), and AS data models (Analysis Services). It is a development tool that allows users to create and implement any SQL Server content form with a convenience identical to that of Visual Studio.

  1. SQL Server Management Studio (SSMS)

The SQL Server Management Studio tool comes with an interactive Graphical User Interface that helps users control a SQL Server database or an instance. Users can gain access to any part of the SQL Server, Azure Synapse Analytics, or the Azure SQL Database and make changes, regulate, supervise, and develop them. 

You may want to look for this tool when you download free SQL Server as it also offers an all-encompassing utility which brings together a wide range of graphical tools along with several rich script editors. These are useful to DBAs and developers of varying skill levels.

  1. Visual Studio Code

The Visual Studio Code enables users to write T-SQL scripts using a compact editor. We are talking about the mssql extension – the official extension for Visual Studio Code that supports SQL Server linking and offers a productive T-SQL editing experience.

  1. Azure Data Studio

This is also a compact and handy editor capable of running SQL various functions including –

  • Executing SQL statements whenever required
  • Organizing preferred database connections
  • Viewing and storing results in text, JSON, or Excel format
  • Exploring database objects in a familiar environment
  • Editing information

Tosska’s Range of SQL Tuning & Query Optimizer Tools

Tosska Technologies offers several solutions to improve database performance through query optimization in SQL. With the goal of introducing new technologies that will help users overcome SQL-related obstacles, they provide a range of software designed using AI technology capable of solving a broad range of database performance issues.

Here’s what this range includes:

  • Tosska SQL Tuning Expert (TSES™) for SQL Server® – Unlike some of the free SQL tools for Windows, this is a powerful tool that doesn’t require professional expertise to tune your SQL queries. The AI engine does all the work, generating the most useful hints and alternate SQL statements that are semantically equivalent to the query that’s been entered to know whether there are better execution plans. You may pick the best option among the ones provided by the engine.
  • Tosska SQL Tuning Expert (TSEM™) for MySQL® – The TSEM™ comes with the A.I. capabilities of the TSE product range. However, this one-button-solution tool is tailored specifically for the MySQL database, tuning MySQL SQL queries without the users’ intervention. Users don’t have to perform manual rewriting or use the hit-and-trial method for each troublesome query, since it’s all handled by our embedded AI engine.
  • Tosska SQL Tuning Expert for Oracle® (TSE™ and TSE Pro™) version 4 – This tool comes with features exclusive to this family of tools, such as SQL rewrite, index exploration, and injecting Oracle hints to help tune SQL queries and boost their performance. It may or may not access your source code depending on the requirements, and the tool comes with a smart Indexes Advisor that offers cost-efficient indexes as per the workload. Make sure you get it when you download free tool and take advantage of this cutting-edge technology!
  • Tosska In-Memory Maestro (TIM™) for Oracle® – The TIM™ transforms the in-memory SQL optimization process into an automatic one and gives suggestions according to the SQL workload in question through our proprietary A.I. engine. It also offers a user-friendly simulation feature that virtually assesses table objects present in the memory for a SQL workload but doesn’t occupy those table objects.

Oracle Database and SQL: The Pros & Cons of Bind Variables

SQL Server database and SQL

Bind Variables are typically considered as one of the major aspects of enhanced SQL query performance. According to Oracle documentation, they serve as a placeholder in a SQL query, getting replaced by a particular value that helps in statement execution.

The use of these variables enables users to create statements that can receive time-running parameters or inputs. One may think of bind variables as “value” given to the SQL query that acts as any function in programming languages. Here, we will talk more about them as well as their advantages and disadvantages in Oracle database and SQL.

Bind Variables: Examples of Their Uses

Consider the following statements in SQL –

Select * from Staff where S_No = 1 ;

Select * from Staff where S_No = :a ;

In the first query, a proper value (1) is applied to operate the query, whereas, in the next query, we have used a bind variable (:a) to operate the statement. This bind variable is given to Oracle when the query is run.

Defining a bind variable in the SQL statements in the place of literal values ensures that a single Parent Cursor is utilized by Oracle for the query. This helps improve database performance because Oracle searches for precise text matches for the query to check whether it already exists in the shared pool. Using a bind variable rather than a literal value saves an expensive hard parse for each run of that query.

Bind variables prove especially useful in OLTP-type environments because their use facilitates soft parsing. In other words, it takes less processing time to re-generate execution plan.

How Bind Variables Help Improve Database Performance

Given below are some advantages of using bind variables:

  1. Optimal Use of Shared Pool – The Shared Pool in Oracle Database needs to hold a single query instead of possibly numerous queries, thanks to bind variables.
  2. Improved Performance Due to Zero Hard Parsing – There is no need for hard parsing because SQL queries only diverge in terms of values.
  3. Decreased “library cache” Latch Contention – Since library cache latch contention is needed during a hard parse, its requirement reduces when bind variables are used.

Shortcomings of Bind Variables

The disadvantages of using bind variables are few. Although bind variables prove excellent if you want to improve Oracle database performance, there are instances where their use can negatively impact results:

  • They can decrease the flow of information needed to compute the best access path for CBO (Cost Based Optimizer). The CBO, in turn, may fail to identify the correct selectivity and create insufficient bad execution plans, opting for a complete table scan instead of using indexes.
  • Sometimes, the CBO requires the literal value to be used by SQL in order to build a robust execution plan. With bind variables, the literal value gets “hidden”, so the CBO is likely to create a subpar plan.

To overcome this issue, Oracle has tried to provide further assistance to the CBO by enabling it to take a look at the bind variable’s value during execution plan creation, which is known as “Bind Variable Peeking”.

Conclusion

The use of bind variables is extremely useful in Oracle database performance, especially when it comes to OLTP environments. However, as a user, you need to be careful while using bind variables. . It is recommended to use bind variables for short runtime SQL, but use literals for long time SQL statements to more information to CBO to generate good query plans.

SQL Query Optimization Tool Online: Top Characteristics

MySQL database and SQL

Data is one of the most important resources in an organization and SQL is the most popular method to store and manipulate it. Therefore, the widely-used Structured Query Language is supported by almost every modern RDBMS around the world.

This is also why database servers are often known as SQL Servers, where the language establishes the manner in which the statements will be formed to fetch the required data. Since modern databases can get rather bulky due to a large number of joined tables, the SQL queries needed to access the right information present inside can get quite complicated as well.

This decreases performance – and SQL query optimization is needed to maintain desired results. Although this can be done manually, there is more than one SQL query optimization tool online available for assistance. Here, we will discuss what SQL query optimization is about, followed by the major characteristics of optimizing tools.

What Query Optimization Means in MySQL Database and SQL

Let’s start with the what and why of SQL query optimization. In basic terms, it is the process of assessing SQL statements and identifying the most productive method to complete a certain task.

Generally, it involves a trial-and-error technique where different statements are tested to compare their performance. The query that exhibits the best performance while still fetching accurate data is then selected.

Although database management systems may already have query optimizers, you can opt for a third-party SQL query optimization tool online as they often provide faster and better results. The average query optimizer produces one or more query plans for each statement to help run the query.

The execution time of every plan is measured and considered as the performance parameter to pick the most efficient one that can run the query in the least time with the same results.

MySQL Database and SQL Query Optimisation: An Example

Let us consider a simple example related to this: suppose a user has to run a statement to fetch around half the information present in a table at a time when the server is already occupied with several connections at once.

This is where the query optimization tool can pick out the optimal query plan that requires minimal resources to fulfill the query. This will also take up fewer server resources. In case the user has to use the same statement at a less busy time, the query optimizer is designed to verify the availability of resources and proceed with loading the complete table in memory instead of using table indexes.

Major Characteristics of a SQL Query Optimization Tool Online

Here’s a look at the three major characteristics that are typically built into a MySQL database and SQL query tuning tool:

Compatibility with Database Engine

A majority of tools are created to support the biggest database engines out there, including Oracle, Microsoft SQL, MySQL, MariaDB, and PostgreSQL. However, some tools may be designed to support a single database management system or to be compatible with an even wider range of engines.

Essential SQL Tuning

One of the core features of every SQL query optimization tool online is the ability to provide basic SQL tuning. It implies rewriting SQL queries to boost their performance, which is done by measuring the time it takes for different versions of the statement to be executed. After this, the version that gives the best results is selected.

Compatibility with Cloud-based Databases

Certain tools come with a feature that allows them to assess and improve the performance of cloud-based database management systems. The best examples of cloud-based databases are AWS RDS and Microsoft SQL Azure. However, not every tool is guaranteed to provide this support, so check whether the one you’re considering does before you make your selection. Also, note that a majority of tools that are compatible with cloud-based MySQL databases and SQL will also work with those present on the premises.