In 2.4.9 it seems that if you do a regex query with an index on the field that you are querying against and you have the "x" options enabled, you will get an error when doing an explain.
Not certain how widespread this behavior is, as I have not looked into it very closely.
> mydb.test.find({c: {$regex: "", $options: "x"}})
> mydb.test.find({c: {$regex: "", $options: "x"}}).explain()
{
"cursor" : "BasicCursor",
"isMultiKey" : false,
"n" : 0,
"nscannedObjects" : 0,
"nscanned" : 0,
"nscannedObjectsAllPlans" : 0,
"nscannedAllPlans" : 0,
"scanAndOrder" : false,
"indexOnly" : false,
"nYields" : 0,
"nChunkSkips" : 0,
"millis" : 0,
"indexBounds" : {
},
"server" : "localhost.localdomain:28000"
}
> mydb.test.ensureIndex({a:1})
Cannot use commands write mode, degrading to compatability mode
WriteResult({ "nInserted" : 1 })
> mydb.test.find({c: {$regex: "", $options: "x"}})
> mydb.test.find({c: {$regex: "", $options: "x"}}).explain()
{
"cursor" : "BasicCursor",
"isMultiKey" : false,
"n" : 0,
"nscannedObjects" : 0,
"nscanned" : 0,
"nscannedObjectsAllPlans" : 0,
"nscannedAllPlans" : 0,
"scanAndOrder" : false,
"indexOnly" : false,
"nYields" : 0,
"nChunkSkips" : 0,
"millis" : 0,
"indexBounds" : {
},
"server" : "localhost.localdomain:28000"
}
> mydb.test.ensureIndex({b:1, c:1})
WriteResult({ "nInserted" : 1 })
> mydb.test.find({c: {$regex: "", $options: "x"}})
> mydb.test.find({c: {$regex: "", $options: "x"}}).explain()
{
"cursor" : "BasicCursor",
"isMultiKey" : false,
"n" : 0,
"nscannedObjects" : 0,
"nscanned" : 0,
"nscannedObjectsAllPlans" : 0,
"nscannedAllPlans" : 0,
"scanAndOrder" : false,
"indexOnly" : false,
"nYields" : 0,
"nChunkSkips" : 0,
"millis" : 0,
"indexBounds" : {
},
"server" : "localhost.localdomain:28000"
}
> mydb.test.dropIndexes()
{
"nIndexesWas" : 4,
"msg" : "non-_id indexes dropped for collection",
"ok" : 1
}
> mydb.test.ensureIndex({c:1})
WriteResult({ "nInserted" : 1 })
> mydb.test.find({c: {$regex: "", $options: "x"}}).explain()
2014-03-06T17:27:41.195-0800 Error: 16863 Error converting //x in field 0 to a JS RegExp object: SyntaxError: Invalid flags supplied to RegExp constructor 'x' at src/mongo/shell/types.js:616
> mydb.test.dropIndexes()
{
"nIndexesWas" : 2,
"msg" : "non-_id indexes dropped for collection",
"ok" : 1
}
> mydb.test.ensureIndex({c:1, d:1})
WriteResult({ "nInserted" : 1 })
> mydb.test.find({c: {$regex: "", $options: "x"}})
> mydb.test.find({c: {$regex: "", $options: "x"}}).explain()
2014-03-06T17:31:15.740-0800 Error: 16863 Error converting //x in field 0 to a JS RegExp object: SyntaxError: Invalid flags supplied to RegExp constructor 'x'
- duplicates
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SERVER-11771 extended options for $regex cannot be displayed in explain output when used on an index
-
- Closed
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