Menu
Implementing an application that looks up a table for mail id presence from a list of around 10 email ids. Tried using $or and $in.
$in seems to give better performance but not significant. Is one more optimized than other?
851
Performance. Because the index contains all fields required by the query, MongoDB can both match the query conditions and return the results using only the index. Querying only the index can be much faster than querying documents outside of the index.
You must apply limit() to the cursor before retrieving any documents from the database. Use limit() to maximize performance and prevent MongoDB from returning more results than required for processing.
Add Appropriate Indexes NoSQL databases require indexes, just like their relational cousins. An index is built from a set of one or more fields to make querying fast.
MongoDB docs have the answer:
"When using $or with <expressions> that are equality checks for the value of the same field, choose the $in operator over the $or operator."
162
$or operator is logical operator where you can define your own login but $in operator is Comparison operator where you can compare you can not put your on logic.
Syntax of $in:
{ field: { $in: [<value1>, <value2>, ... <valueN> ] } }
Example:
db.account.find( { qty: { $in: [ 5, 15 ] } } )
Syntax of $or:
{ $or: [ { <expression1> }, { <expression2> }, ... , { <expressionN> } ] }
Example:
db.account.find( { $or: [ { quantity: { $lt: 20 } }, { price: 10 } ] } )
Note: Account is your collection name
21
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
