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tdengine

max length of each data row can be more than 16k characters in TDengine database


From official documentation, the max length of each data row is 16k characters, but I can still successfully create a table with more than 16k characters each row.

taos> create table tb1(ts timestamp, c1 binary(1024), c2 binary(1024), c3 binary(1024), c4 binary(1024), c5 binary(1024), c6 binary(1024), c7 binary(1024), c8 binary(1024), c9 b
inary(1024), c10 binary(1024), c11 binary(1024), c12 binary(1024), c13 binary(1024), c14 binary(1024), c15 binary(1024), c16 binary(1024));
Query OK, 0 of 0 row(s) in database (0.004552s)

taos> show tables;
           table_name           |      created_time       | columns |          stable_name           |          uid          |     tid     |    vgId     |
==========================================================================================================================================================
 tb1                            | 2021-09-30 22:01:21.181 |      17 |                                |       844424997251312 |           4 |           3 |
Query OK, 1 row(s) in set (0.002585s)

what is the max length of each data row?


Solution

  • I don't know which version of TDengine you use, but from the latest official document:

    Maximum length of record: including 8 bytes as timestamp, no more than 48K bytes (it's 16K bytes prior to 2.1.7.0. each column of BINARY/NCHAR type will occupy an additional 2 bytes of storage location)