Сompiling large queries takes a long time

[alex-tselikovsky]

When generating a large query, performance drops significantly. Problem identified during research of Helper.cs (https://github.com/sqlkata/querybuilder/blob/master/QueryBuilder/Helper.cs) in the ‘ReplaceAll’ method on line 92 where string concatenation occurs.

Replacing it with the code below solves the problem.
.Aggregate(new StringBuilder(splitted.First()), (prev, right) => prev.Append(right))
Pull Request for this reason can be found at the link.
c54f509

[ahmad-moussawi]

@alex-tselikovsky do you have any benchmarks

[for7raid]

sound reasonable, but implementation have a questions.
callback(index) + item reproduces the same issue - multiple coping strings in memory. so we have to replace both select and aggregate using in one expression, like reduce in javascript.

[ahmad-moussawi]

Closing this since no feedback.

[viveks7]

@ahmad-moussawi We are also seeing a similar pattern with generating larger queries where the bulk of the allocation is happening in the ReplaceAll method.