Unexpected Memory Exhaustion scenarios When Using Nested Loops in PHP 8.2 with Large Data Sets
I'm confused about I'm experiencing a `Fatal behavior: Allowed memory size of X bytes exhausted` when attempting to process large datasets using nested loops in PHP 8.2. My application pulls data from a MySQL database and processes each record in a loop, which then triggers another loop to perform operations on each record's related data. Here’s a simplified version of my code: ```php // Assuming PDO is set up and $db is the PDO instance $query = $db->query('SELECT * FROM main_table'); $records = $query->fetchAll(PDO::FETCH_ASSOC); foreach ($records as $record) { // Process each record $relatedQuery = $db->prepare('SELECT * FROM related_table WHERE main_id = :id'); $relatedQuery->execute([':id' => $record['id']]); $relatedRecords = $relatedQuery->fetchAll(PDO::FETCH_ASSOC); foreach ($relatedRecords as $relatedRecord) { // Some complex processing $processedData[] = $someProcessingFunction($relatedRecord); } } ``` Even when the dataset isn't particularly large, I'm noticing this memory exhaustion behavior. I've tried increasing the memory limit in my `php.ini`: ```ini memory_limit = 512M ``` However, this didn't resolve the scenario. I've also enabled behavior reporting, which shows the behavior points to the nested loops, but the amount of data I'm processing should not require that much memory. Is there a more efficient way to handle this kind of nested querying without running into memory issues? Also, are there any design patterns I should be considering to avoid this in the future? Any insights would be greatly appreciated. Is there a better approach?