I want to know what unpredictable exceptions will occur when using CompletableFuture to asynchronously query the database in Stream's foreach?

I want to know what unpredictable exceptions will occur when using CompletableFuture to asynchronously query the database in Stream"s foreach? Does that mean there will be a problem? . Please also let me know. Thank you!

Nov.22,2021
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b3b576-2c2a1.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b3b576-2c2a1.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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