Application programs can execute `INSERT` statement through client libraries to insert rows. The TDengine CLI can also be used to manually insert data.
`ts1` is Unix timestamp, the timestamps which is larger than the difference between current time and KEEP in config is only allowed. For further detail, refer to [TDengine SQL insert timestamp section](../../../taos-sql/insert).
`ts1` and `ts2` is Unix timestamp, the timestamps which is larger than the difference between current time and KEEP in config is only allowed. For further detail, refer to [TDengine SQL insert timestamp section](../../../taos-sql/insert).
`ts1`, `ts2` and `ts3` is Unix timestamp, the timestamps which is larger than the difference between current time and KEEP in config is only allowed. For further detail, refer to [TDengine SQL insert timestamp section](../../../taos-sql/insert).
- Inserting in batches can improve performance. The higher the batch size, the better the performance. Please note that a single row can't exceed 48K bytes and each SQL statement can't exceed 1MB.
- Inserting with multiple threads can also improve performance. However, at a certain point, increasing the number of threads no longer offers any benefit and can even decrease performance due to the overhead involved in frequent thread switching. The optimal number of threads for a system depends on the processing capabilities and configuration of the server, the configuration of the database, the data schema, and the batch size for writing data. In general, more powerful clients and servers can support higher numbers of concurrently writing threads. Given a sufficiently powerful server, a higher number of vgroups for a database also increases the number of concurrent writes. Finally, a simpler data schema enables more concurrent writes as well.
- If the timestamp of a new record already exists in a table, columns with new data for that timestamp replace old data with new data, while columns without new data are not affected.
- The timestamp to be inserted must be newer than the timestamp of subtracting current time by the parameter `KEEP`. If `KEEP` is set to 3650 days, then the data older than 3650 days ago can't be inserted. The timestamp to be inserted cannot be newer than the timestamp of current time plus parameter `DURATION`. If `DURATION` is set to 2, the data newer than 2 days later can't be inserted.
2. Please note that `use db` can't be used with a REST connection because REST connections are stateless, so in the samples `dbName.tbName` is used to specify the table name.
TDengine also provides API support for parameter binding. Similar to MySQL, only `?` can be used in these APIs to represent the parameters to bind. This avoids the resource consumption of SQL syntax parsing when writing data through the parameter binding interface, thus significantly improving write performance in most cases.