• 上层：TrueNAS | Debian Server | Windows | Ubuntu Desktop
• 底层：Proxmox VE
• 硬件：主要硬件考虑华南全家桶（性价比）
• 外挂：树莓派、摄像头...

• ZFS是一个先进的文件系统。源自Oracle的OpenSolaris系统中的项目，自OpenSolaris闭源后，该ZFS也闭源。后原核心开发成员出走成立OpenZFS。
• 特点：存储池；写时拷贝；快照；数据完整性验证和自动修复；RAID-Z；最大单个文件大小为 16 EB（1 EB = 1024 PB）；最大 256 千万亿（256*1015 ）的 ZB（1 ZB = 1024 EB）的存储

• 查看正在进行中的query

-- 普通查询
SELECT query_id, read_rows, total_rows_approx, memory_usage, initial_user, initial_address, elapsed, query, client_hostname, memory_usage FROM system.processes FORMAT Vertical;
-- 多副本联合查询
SELECT query_id, read_rows, total_rows_approx, memory_usage, initial_user, initial_address, elapsed, query, client_hostname, memory_usage FROM clusterAllReplicas('replicated', 'system', 'processes') FORMAT Vertical;
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• 查看某条query的重要信息

SELECT query_id, query, projections, query_start_time, query_duration_ms, read_rows, written_rows, result_rows, read_rows, read_bytes FROM system.query_log WHERE query_id='<query_id>' FORMAT Vertical;
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• 查看最近的query

-- 普通查询
SELECT query_id, query_start_time, query FROM system.query_log ORDER BY query_start_time DESC LIMIT 10 FORMAT Vertical;
-- 多副本联合查询
SELECT query_id, query_start_time, query FROM clusterAllReplicas('replicated', 'system', 'query_log') ORDER BY query_start_time DESC LIMIT 10 FORMAT Vertical;
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• 查看锁表情况

-- 普通查询
SELECT table, total_replicas, active_replicas, queue_size, future_parts, inserts_in_queue, merges_in_queue, part_mutations_in_queue, replica_path, zookeeper_exception, replica_is_active, last_queue_update, last_queue_update_exception FROM system.replicas WHERE is_readonly FORMAT Vertical;
-- 多副本联合查询
SELECT table, total_replicas, active_replicas, queue_size, future_parts, inserts_in_queue, merges_in_queue, part_mutations_in_queue, replica_path, zookeeper_exception, replica_is_active, last_queue_update, last_queue_update_exception FROM clusterAllReplicas('replicated', 'system', 'replicas') WHERE is_readonly FORMAT Vertical;
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• 查看merge情况

-- 普通查询
SELECT table, progress, elapsed, memory_usage FROM system.merges;
-- 多副本联合查询
SELECT table, progress, elapsed, memory_usage FROM clusterAllReplicas('replicated', 'system', 'merges');
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• 查看mutation进程

-- 普通查询
SELECT mutation_id, is_done, command, table, parts_to_do, parts_to_do_names FROM system.mutations WHERE command = 'MATERIALIZE PROJECTION deviceaddress_one' FORMAT Vertical;
-- 多副本联合查询
SELECT mutation_id, is_done, command, table, parts_to_do, parts_to_do_names FROM clusterAllReplicas('replicated', 'system', 'mutations') WHERE command = 'MATERIALIZE PROJECTION deviceaddress_one' FORMAT Vertical;
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