SchemeShard: limit & consumption metrics

[CyberROFL]

Limits:

ydb/ydb/core/tx/schemeshard/schemeshard_types.h

Lines 27 to 60 in 4efd77c

	struct TSchemeLimits {
	// Used for backward compatability in case of old databases without explicit limits
	static constexpr ui64 MaxPathsCompat = 200*1000;
	static constexpr ui64 MaxObjectsInBackup = 10*1000;
	// path
	ui64 MaxDepth = 32;
	ui64 MaxPaths = MaxObjectsInBackup;
	ui64 MaxChildrenInDir = 100*1000;
	ui64 MaxAclBytesSize = 10 << 10;
	ui64 MaxPathElementLength = 255;
	TString ExtraPathSymbolsAllowed = "!\"#$%&'()*+,-.:;<=>?@[\\]^_`{|}~";
	// table
	ui64 MaxTableColumns = 200;
	ui64 MaxColumnTableColumns = 10000;
	ui64 MaxTableColumnNameLength = 255;
	ui64 MaxTableKeyColumns = 20;
	ui64 MaxTableIndices = 20;
	ui64 MaxTableCdcStreams = 5;
	ui64 MaxShards = 200*1000; // In each database
	ui64 MaxShardsInPath = 35*1000; // In each path in database
	ui64 MaxConsistentCopyTargets = MaxObjectsInBackup;
	// pq group
	ui64 MaxPQPartitions = 1000000;
	// export & import
	ui64 MaxExports = 10;
	ui64 MaxImports = 10;
	static TSchemeLimits FromProto(const NKikimrScheme::TSchemeLimits& proto);
	NKikimrScheme::TSchemeLimits AsProto() const;
	};