CanForEach()usetheparentofaSelectMany()?
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ByConity 技术详解之 Hive 外表和数据湖
enable_optimizer : 开启优化器 - dialect_type ANSI: 使用标准 Ansi SQL - s3_use_read_ahead: 关闭 S3 的 ReadAhead 功能 - remote_read_min_bytes_for_seek: 两个读之间如果间隔小于... CREATE TABLE hudi.stock_ticks_mor_rtENGINE = CnchHudi('thrift://hivemetastore:9083', 'default', 'stock_ticks_mor_rt')-- MOR 查询SELECT symbol, max(ts)FROM stock_ticks_mor_rtGROUP BY sy...
使用mysql-sniffer 查看MySQL当前执行的语句
Usage ./mysql-sniffer [-d] -i eth0 -p 3306,3307,3308 -l /var/log/mysql-sniffer/ -e stderr [-d] -i eth0 -r 3000-4000 -d daemon mode. -s how often to split the log file(minu... default to 3306. Multiple ports should be splited by ','. eg. 3306,3307 this option has no effect when -f is set. -r port range, Don't use -r and -p at the same time -...
使用 mysql-sniffer 查看MySQL当前执行的语句
Usage ./mysql-sniffer [-d] -i eth0 -p 3306,3307,3308 -l /var/log/mysql-sniffer/ -e stderr [-d] -i eth0 -r 3000-4000 -d daemon mode. -s how often to split the log file(minu... default to 3306. Multiple ports should be splited by ','. eg. 3306,3307 this option has no effect when -f is set. -r port range, Don't use -r and -p at the same time -...
ByteHouse MaterializedMySQL 增强优化
> 更多技术交流、求职机会,欢迎关注**字节跳动数据平台微信公众号,回复【1】进入官方交流群**# 前言社区版 ClickHouse 推出了[MaterializedMySQL数据库引擎](https://xie.infoq.cn/link?target=https%3A%2F%2F... 用户权限 MaterializeMySQL 表引擎用户必须具备 MySQL 库的 RELOAD、REPLICATION SLAVE、REPLICATION CLIENT 以及 SELECT PRIVILEGE 权限 支持的 MySQL 版本 5.65.78.0## 源端数据准备在 MySQL 数据库里...
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CanForEach()usetheparentofaSelectMany()?
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CanForEach()usetheparentofaSelectMany()?
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数组函数
Otherwise, it isn’t clear which type of array to create. That is, you can’t use this function to create an empty array (to do that, use the ‘emptyArray*’ function described above). Syntax sql a... Example sql SELECT array(1,2,3);plain%20text ┌─array(1, 2, 3)─┐│ [1, 2, 3] │└────────────────┘arrayAllReturns 1 if func returns something other than 0 for all the eleme...
哈希函数
function instead. If you want to get the same result as output by the md5sum utility, use lower(hex(MD5(s))). Syntax sql select MD5(string)Arguments string – A string Returned value The Value of M... while SHA-224 and SHA-256 process about 2.2 million). We recommend using this function only in cases when you need a specific hash function and you can’t select it. Even in these cases, we recomme...
生产并消费消息(SSL 方式)
public class SimpleProducerSSL { private static final String host = "your-end-point"; //AMQP协议公网接入地址。 private static final int port = 5671; private static final String userName ... actory.newConnection(); // 创建Channel Channel channel = connection.createChannel(); // 开启publish confirm(可选,推荐开启) channel.confirmSelect(); // 创建Exchange...
SQL Statements
Dumps the query AST.Syntax sql AST queryOutput Column Description explain The parsedASTof the statement Example sql AST SELECT 1;plain%20text Explain ParsedAST (children 1) SelectWithUnionQuery... They just perform a read from another table on each access. In other words, a normal view is nothing more than a saved query. When reading from a view, this saved query is used as a subquery in the...
跳数索引
当尝试处理大量数据时,查询性能可能会恶化,因为可能需要对每个列值进行完整扫描才能应用 WHERE 子句条件。为了解决这个问题,ByteHouse 支持跳数索引(Data Skipping Index),使人们能够跳过一些确认没有匹配值的重要... added successfullySELECT sum(id) FROM test_skipindex WHERE key_i = 1;如果我们运行下面的命令, SQL --Simple query to select all rows from the table test_skipindex where the key_i column has values of ...
WebSocket API
若二者都非空则按照ssml字段 - speaker 发音人,具体见附录:发音人列表 string 是 - audio_config 补充参数 object 否 audio_config.format 输出音频编码格式,wav/mp3/aac string 否 mp3 audio_config.sample_rate... "start_time": "0", "end_time": "0.025" }, ... ]} 参考示例流式调用方式参考公共WebSocket流式协议 GolangGo // Code sample:// use websocket client to invoke SAMI ...
清理空间(pg_repack)
UPDATE 和 DELETE 操作记录到日志表中。 创建新表,与原表的行列相同。 对新表执行 INSERT INTO SELECT,将原表数据导入新表。 在新表中创建和原表一一对应的索引。 将日志表里的变更应用到新表。 将新表及其索... jobs=NUM Use this many parallel jobs for each table -i, --index=INDEX move only the specified index -x, --only-indexes move only indexes of the specified table -T, --...
类型转化函数
use 中正常使用。 CASTConverts an input value to the specified data type. Unlike the reinterpret function, CAST tries to present the same value using the new data type. If the conversion can not be d... Returned value Converted value.!!! note "Note"If the input value does not fit the bounds of the target type, the result overflows. For example, CAST(-1, 'UInt8') returns 255 . Examples sql SELECT C...
ByConity 技术详解之 Hive 外表和数据湖
enable_optimizer : 开启优化器 - dialect_type ANSI: 使用标准 Ansi SQL - s3_use_read_ahead: 关闭 S3 的 ReadAhead 功能 - remote_read_min_bytes_for_seek: 两个读之间如果间隔小于... CREATE TABLE hudi.stock_ticks_mor_rtENGINE = CnchHudi('thrift://hivemetastore:9083', 'default', 'stock_ticks_mor_rt')-- MOR 查询SELECT symbol, max(ts)FROM stock_ticks_mor_rtGROUP BY sy...
