Database snapshots cannot be created if the role state is RESOLVING. We can get this information by accessing a dynamic management view
sys.availability_groups. We can use either the system dynamic management function sys.dm_io_virtual_file_stats or a
system function fn_virtualfilestats to get this information. We need to pass database and file id details about that
specific database file for which we are looking for IO statistics. Any record deleted from SQL Server is not actually deleted from its physical data pages but
marked as “To BE DELETED” or “GHOSTED” by changing a bit in the row header.
- I also utilize automation tools to streamline routine tasks, freeing up time for more complex challenges.
- SQL is an open-source language developed by IBM, while T-SQL is created and owned by Microsoft.
- In terms of architecture, I’ve designed schemas, tables, views, and indexes while ensuring the integrity, security, and performance of databases.
- Many online, mobile, geospatial, and analytics applications utilise PostgreSQL as their primary data storage or data warehouse.
- Earlier we have only one option to initialize secondary replica that is using backup, copy and restore database
operation.
It can be used in a SELECT, INSERT, UPDATE, or DELETE statement. The SQL BETWEEN Condition will return the records where the expression is within the range of value1 and value2. The ORDER BY statement in SQL is used to sort the fetched data in either ascending or descending according to one or more columns.
What are aggregate and scalar functions?
In Oracle 11g, you can create an auto-increment column by using a combination of a sequence and a BEFORE INSERT trigger. An alternative is a non-clustered index, which does not order the records on a disk but does offer other benefits of indexes. This can be done using either the DECODE function or the CASE statement.
Overall, SQL is a query language that communicates with databases. As a database administrator, you’re the bridge between raw data and an organization’s ability to use it effectively. The individual in this role is not only expected to be proficient with the latest database technologies, but also must ensure seamless integration with existing systems. By asking this question, employers are gauging your technical expertise, problem-solving skills, and ability to manage change within an organization. A primary key is a column or set of columns that uniquely identifies a row in a table.
Can You Explain the Different Editions of SQL Server?
There would information such as the time it took to execute that Job and details about the error that occurred. Inside SSMS, in Object Explorer under SQL Server Agent look for Job Activity Monitor. The job activity monitor displays the current status of all the jobs on the instance. Choose a particular job that failed, right-click, and choose view history from the drop-down menu. The simplest answer to this is “Clustered and Non-Clustered Indexes”. There are other types of Indexes that can be mentioned such as Unique, XML, Spatial and Filtered Indexes.
- The MERGE statement allows you to check a set of data for a condition, and UPDATE a record if it exists or INSERT a record if it doesn’t exist.
- If the underlying tables have been updated, the view will load these results.
- Yes, database snapshots can be created of primary or secondary databases if their role state is
either PRIMARY or SECONDARY. - In a trigger, we first specify when the trigger is to be executed and then the action to be performed when the trigger executes.
In SQL, there is a built-in function called GetDate() which helps to return the current timestamp/date. Both Char and Varchar2 are used for characters datatype but varchar2 is used for character strings of variable length whereas Char is used for strings of fixed length. For example, char(10) can only store 10 characters and will not be able to how to become a sql dba developer store a string of any other length whereas varchar2(10) can store any length i.e 6,8,2 in this variable. If the SQL table has duplicate rows, the duplicate rows must be removed. When none of the WHEN conditions return true, the ELSE statement is executed. The UNIQUE Constraint prevents identical values in a column from appearing in two records.