Channi Studies

A function is a stored program that you can pass a parameters into to return a value. There are lots of functions offered by MySQL that can be found in following reference manual.  MySQL :: MySQL 8.4 Reference Manual :: 14.1 Built-In Function and Operator Reference14.1 Built-In Function and Operator Reference The following table lists each built-in (native) function and operator and provides a s..

A JOIN clause is used to combine rows from two or more tables, based on a related column between them.We will take a look into INNER JOIN, LEFT JOIN, and RIGHT JOIN.  Continued from the previous post, customers table consists of 3 columns: customer_id (PRIMARY KEY), first_name, last_nametransactions table consists of 3 columns: transaction_id (PRIMARY KEY), amount, customer_id (FOREIGN KEY)INSER..

Double Hashing is an open-addressing collision resolution technique that uses 2 different hash functions to compute bucket indices. Using hash functions h₁ and h₂, a key's index in the table is computed with the formula (h₁(key) + 𝑖 * h₂(key)) mod (tablesize) Inserting a key uses the formula, starting with 𝑖 = 0, repeatedly search hash table buckets until an empty bucket is found.Each time an ..

Linear Probing A hash table with linear probing handles a collision by starting at the key's mapped bucket, and then linearly searches subsequent buckets until an empty bucket is found.  Item 124 should be inserted into bucket 4 since 124 % 10 = 4, but bucket 4 is already occupied, so it searched for next null (empty) bucket appearing linearly starting from the original bucket. Since bucket 5 wa..