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What is the most performant way to get the total number of records from a table?

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What is the most performant way to get the total number of records from a table?

When I need to count the number of table rows, I use metadata – it is the fastest way. Do not be afraid of the old bug case I described. If there is a need to quickly count the number of rows from a perspective of some field or by condition, I try using indexed views or filtered indexes.

What is the best database for large data?

MongoDB is also considered to be the best database for large amounts of text and the best database for large data.

What database structure does Facebook use?

MySQL
MySQL is the primary database used by Facebook for storing all the social data. It started with the InnoDB MySQL database engine & then wrote MyRocksDB, which was eventually used as the MySQL Database engine. Memcache sits in front of MySQL as a cache.

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What are 3 ways to get a count of the number of records in a table?

Three ways to do the counting:

  1. SELECT COUNT(*) AS row_count FROM your_table WHERE…
  2. Use the “num_rows()” function (its precise name and syntax depend of the extension you use, like MySQLi and PDO) on the result set to retrieve the number of rows.
  3. Iterate through all the rows from the result set and keep a counter.

How load large data from database?

What is the best way to load huge result set in memory?

  1. 1) open data reader approach for reading source and target data:
  2. 2) Chunk by chunk reading approach for reading source and target data:
  3. 3) Chunk by chunk reading approach for reading source and target data:

How do I find my Facebook database?

In the “Settings” sidebar, click “Your Facebook Information.” You’ll see a few different areas to explore. Click “View” to the right of “Access Your Information.” Here, you’ll see all your Facebook information organized into several categories.

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How does Facebook handle big data?

Apart from analyzing user data, Facebook has other ways of determining user behavior. Tracking cookies: Facebook tracks its users across the web by using tracking cookies. If a user is logged into Facebook and simultaneously browses other websites, Facebook can track the sites they are visiting.

What is the size of each record in a database?

Each record is about 500 bytes in size. To make it more concrete: in the GUI of my application I have a text field where I can enter a string. Above the text field I have a table displaying the (first N, e.g. 100) records that match the string in the text field.

What is the fastest way to index a large data set?

Prefer full table scans to index accesses – For large data sets, full table scans are often faster than range scans and other types of index lookups. Even if you look at 1\% fr rows or less, a full table scan may be faster. Avoid joins to large tables Joining of large data sets using nested loops is very expensive.

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How many iOS does it take to retrieve 100 rows/SEC?

Now if your data is fully on disk (both data and index) you would need 2+ IOs to retrieve the row – which means you get about 100 rows/sec. Note: multiple drives do not really help a lot as we’re speaking about single thread/query here. So the difference is 3,000x!

How many rows per second does it take to read a table?

Consider a table which has 100-byte rows. With decent SCSI drives, we can get 100MB/sec read speed which gives us about 1,000,000 rows per second for fully sequential access, with jam-packed rows – quite possibly a scenario for MyISAM tables.

https://www.youtube.com/watch?v=HKxls7qCZPE