Simplest way is to use the data dictionaries provided by Oracle. And you can depend on the results if the schema is up to date with the statistics. Use the following query to get the table list and their number of rows (records). SELECT table_name, num_rows FROM user_tables; OR SELECT table_name, num_rows FROM all_tables WHERE …
get tables and their number of rows in Oracle Database Schema Read More »
Histogram:A histogram is a special type of column statistic that provides more detailed information about the data distribution in a table column. Purpose of Histograms:By default the optimizer assumes a uniform distribution of rows across the distinct values in a column. For columns that contain data skew (a nonuniform distribution of data within the column), …
We will get this when we are trying to update a row in a table, for which there will be two or more corresponding records. Table 1: tc11 tcl2 t1 a t2 b t3 c t4 d Table 2: tc21 tc22 b1 a b2 b b3 c b4 d Table 3: tc31 tc32 t1 b1 …
ORA-30926: unable to get a stable set of rows in the source tables Read More »
Replace will replace the character or string with the given character/string for every occurrence of the character/string.Translate will replace the character with another character given not by the string/multiple characters Case 1: SELECT REPLACE(‘Jack and Jue’,’J’,’Bl’) replace_str,TRANSLATE(‘Jack and Jue’,’J’,’Bl’) translate_strFROM DUAL; Case 2: SELECT REPLACE(‘Jack and Jue’,’J’,”) replace_str,TRANSLATE(‘Jack and Jue’,’J’,”) translate_strFROM DUAL;
