Server Status Variables Whether the client connection uses compression in the client/server protocol. As of MySQL 8.0.18, this status variable is deprecated; expect it to be removed in a future version of MySQL. See Configuring Legacy Connection Compression. The name of the compression algorithm in use for the current connection to the server. The value can be any algorithm permitted in the value of the  protocol_compression_algorithms  system variable. For example, the value is  uncompressed  if the connection does not use compression, or  zlib  if the connection uses the  zlib  algorithm. • Compression_algorithm • Compression_level • Connection_errors_ xxx This variable was added in MySQL 8.0.18. For more information, see Section 4.2.8, “Connection Compression Control” . These variables provide information about errors that occur during the client connection process. They are global only and represent error counts aggregated across connections from all hosts. These variables track errors not accounted for by the host cache (see Section 5.1.12.3, “DNS Lookups and the Host Cache” ), such as errors that are not associated with TCP connections, occur very early in the The compression level in use for the current connection to the server. The value is 6 for  zlib connections (the default  zlib  algorithm compression level), 1 to 22 for  zstd  connections, and 0 for uncompressed  connections. For more information, see Section 4.2.8, “Connection Compression Control” . This variable was added in MySQL 8.0.18. 950