Cumulusmx.db
This page is the new Cumulusmx.db page. This page and subpages hold a complete rewrite of the Webtags related pages.
The information that was on this old Cumulusmx.db page has been moved to Cumulusmx.db (preserving history). You are advised to use that page until this page is ready and this message has been removed. If any questions or remarks please send a PM to HansR on the forum. Do not use the discussion tab unless accompanied by a PM: there is no automated signal to HansR if you use that page.
This page and its subpages will document the Cumulusmx.db from the point of view of the CumulusMX software and not the Cumulus 1 legacy software. Cumulus 1 is no longer maintained and will eventually disappear. If you are still using it, please refer to the original Cumulusmx.db (preserving history) page where @sfws has tried to give both packages equal value. That effort is no longer maintained in this Webtags page. We hope you will understand this approach.
Please do not edit this page while it is being worked on i.e. while this message is still here.
Introduction
In CumulusMX version 3, this database contains the Recent History. The SqlCache and the sqlite_sequence tables are not for normal usage. It is an SQLite datebase only to be maintained by CumulusMX. When removed it will be rebuilt.
The database is stored in the data directory so its relative path is data/cumulusmx.db (case dependent on Linux).
A good tool to inspect this database is DB Browser for SQLite (external site). Editing the database takes you to unsupported territory but it might be educational to inspect.
Note: The CumulusMX Weather Diary also uses a SQLite database stored in data/diary.db.
Database Tables included
The following table lists the tables found in this database, indicating which release added the table, and where further details can be found.
| Table name | How MX updates | Introduced | Description | Editor within MX | Further details |
|---|---|---|---|---|---|
| RecentData | Updated once a minute when MX is running | MX beta 3.0.0
|
The update.txt for CumulusMX at release 3.12.0 (beta build 3134) states "Change: Cumulus MX now uses a persistent database to store the recent 1 minute data
- This means that charts, recent web tags, and internal calculations for trends and periodic values will be more accurate after a restart - If Cumulus MX is offline for a prolonged period, data for that offline period will obviously still be at the station logging interval resolution". |
No editor for Cumulus user | Recent history and #RecentData table |
| SqlCache | Updated when certain conditions are met and SQL is queued | MX 3.21.0 | The update.txt for CumulusMX at release 3.21.0 states "New - Failed MySQL commands can now be individually edited/deleted
Changed - Failed MySQL commands are now stored in the SQLite database to persist across Cumulus runs" |
Edit or purge the failed MySQL command queue using Utils menu -->> PurgeMySQL | MySqlConnect and #SqlCache table |
| StandardData | At time of writing, the current MX release does not use this table | MX beta 3.0.0
(always in file) |
In this forum post Steve Loft describes this table as being for a possible future enhancement. It is believed this is the table that Steve had developed in Cumulus 2, as a replacement for the Monthly_log_files. | At time of writing, the current MX release does not use this table | #StandardData table |
| sqlite_sequence | Developer has not stated when updated | MX 3.21.0 | Developer has not supplied a description | Not known | #sqlite_sequence table |
RecentData table
This table has the following columns:
| Column number # | Column name | Column type | Properties | Description | Example column value |
|---|---|---|---|---|---|
| 0 | Timestamp | datetime | Primary Key, can never be NULL, No Default Value, | Dates and times for the last 7 days, at whatever interval available (at logging interval for historic archive data, at one minute intervals while MX is running) | 2021-07-31 19:44:00 |
| 1 | WindSpeed | float | Not NULL, No Default Value | The average wind speed (see Wind_measurement#Weather_Stations_and_Cumulus for links) calculated at the stated time, if necessary converted to units requested | 2.2593056529 |
| 2 | WindGust | float | Not NULL, No Default Value | The spot gust speed recorded at the stated time, if necessary converted to units requested | 6.99691241605804 |
| 3 | WindLatest | float | Not NULL, No Default Value | The spot latest wind speed recorded at the stated time, if necessary converted to units requested | 3.15989597323001 |
| 4 | WindDir | integer | Not NULL, No Default Value | The wind bearing (0 =calm), (1 to 360 = number of degrees) | 315 |
| 5 | WindAvgDir | integer | Not NULL, No Default Value | The average wind bearing over the defined period | 270 |
| 6 | OutsideTemp | float | Not NULL, No Default Value | The measured outside air temperature, if necessary converted to units requested | 17.0 |
| 7 | WindChill | float | Not NULL, No Default Value | The wind chill, either calculated by MX, or supplied by weather station. (Note: strictly only valid for low temperatures and significant wind speeds) | (In the example used here, temperature in previous column was too high for wind chill, so the value was set to agree with 'OutsideTemp' column instead) |
| 8 | DewPoint | float | Not NULL, No Default Value | The dew point, either calculated by MX, or supplied by weather station, for the stated time. | 11.9134549845367 |
| 9 | HeatIndex | float | Not NULL, No Default Value | The USA Heat index as calculated by Cumulus for the stated time (if the temperature is high enough) | (In the example used here, temperature in 'OutsideTemp' column was too low for heat index, so the value was set to agree with 'OutsideTemp' column instead) |
| 10 | Humidity | float (1 decimal place) | Not NULL, No Default Value | The Relative Humidity reported by the station at the stated time | 72.0 |
| 11 | Pressure | float | Not NULL, No Default Value | The sea level pressure at the stated time, either as reported by the station or calculated by Cumulus from the absolute pressure reported by the station, if necessary converted to units requested | 996.400024414062 |
| 12 | RainToday | float | Not NULL, No Default Value | The rainfall for today so far, calculated by Cumulus from the rain counter (column 15) now minus the rain counter at start of day, if necessary converted to units requested | 4.5 |
| 13 | SolarRad | integer | Not NULL, No Default Value | Solar radiation value reported by station at stated time | 200 |
| 14 | UV | float | Not NULL, No Default Value | The Ultra Violet Index reported by station at stated time | 3.0 |
| 15 | raincounter | float | Not NULL, No Default Value | The rain counter is used by Cumulus for all rainfall outputs, this is its value at stated time | 550.4 |
| 16 | FeelsLike | float | Not NULL, No Default Value | The Feels Like temperature calculated by MX at stated time | 17.0782773978147 |
| 17 | Humidex | float | Not NULL, No Default Value | The Canadian Humidity Index, calculated by Cumulus at the stated time | 19.1775362738161 |
| 18 | AppTemp | float | Not NULL, No Default Value | The Apparent temperature, calculated by MX at the stated time | 16.8864476063546 |
| 19 | IndoorTemp | float | Not NULL, No Default Value | The indoor temperature directly as reported by station at stated time | 120.89999961853 |
| 20 | IndoorHumidity | integer (0 decimal places, contrast with column 10) | Not NULL, No Default Value | The indoor relative humidity directly as reported by station at stated time | 61 |
| 21 | SolarMax | integer | Not NULL, No Default Value | The calculated maximum value for solar radiation at stated time | 1026 |
| 22 | Pm2p5 | float | Not NULL, No Default Value | Air Quality expressed in terms of particulate matter of 2.5 μm, or less, (?? Rolling 24 hours average ??) | 1.5 |
| 23 | Pm10 | float | Not NULL, No Default Value | Air Quality expressed in terms of particulate matter of 10 μm, or less, (?? Rolling 24 hours average ??) | 1.7 |
| 24 | RainRate | float | Not NULL, No Default Value | The rainfall rate calculated for the stated time | 303.2 |
See Recent history page for more details.
SqlCache table
There is a MX setting (Settings -->> MySQL settings -->> General Options -->> Buffer commands on failure) that when enabled allows failed commands to be stored here.
This table holds a list of MySQL commands that are in the queue for MySqlConnect to run again.
Commands that fail because the database server is down are added to the queue when the setting is enabled (although MX will not save more than one query referencing same primary key). Because the error returned by the server cannot be predetermined, MX instead checks the error returned is not one of the following reasons before adding it to queue:
- ParseError (the query does not make sense)
- EmptyQuery (query has not been specified)
- TooBigSelect (there is a limit to how much data can be selected)
- InvalidUseOfNull (the schema has to say for each column whether null is permitted)
- MixOfGroupFunctionAndFields (syntax can't mix these)
- SyntaxError (an error in the SQL syntax)
- TooLongString (there is a limit to what can be input)
- WrongColumnName (the column name must exist in the referenced table/view)
- DuplicateUnique (you can't insert a new row with same primary key as an existing row)
- PrimaryCannotHaveNull (the primary key must be set to a specific value)
- DivisionByZero (certain mathematical operations cannot be handled)
Here is the relevant create table instruction, so this tells you the 2 fields in the table as Mark Crossley created it:
CREATE TABLE "SqlCache"( "key" integer primary key autoincrement not null, "statement" varchar)
The table contents are simple to explain, each time a new command is stored it is assigned a new number (that is automatically incremented from last number used) and the command itself is stored in a variable text length entry.
StandardData table
At time of writing this documentation, the latest MX release does not use this table, and it has zero rows. A forum post by Steve Loft about a database based logging proposal for Cumulus 3 (MX) confirms the original purpose was to improve the ability to Correct Extremes Records by storing the most frequent and accurate extremes possible.
While that does not specifically explain this table, his choice of table name suggests he was planning to either replace, or duplicate, the use of text files for logging data. It appears he was actually thinking about implementing Monthly_log_files#Enhancement never implemented from his inclusion of "Lo" and "Hi" values in the column list.
The only alternative theory is Steve Loft actually thought he could improve on the Recent history functionality, by storing the highest and lowest readings read from weather station in-between the one minute resolution.
Here is the relevant create table instruction, so this tells you the 17 fields in the table as Steve created it (these have never been changed):
CREATE TABLE "StandardData"( "Timestamp" datetime primary key not null , "Interval" integer , "OutTemp" float , "LoOutTemp" float , "HiOutTemp" float , "DewPoint" float , "LoDewPoint" float , "HiDewPoint" float , "WindChill" float , "LoWindChill" float , "HiWindChill" float , "InTemp" float , "LoInTemp" float , "HiInTemp" float , "Pressure" float , "LoPressure" float , "HiPressure" float )
sqlite_sequence table
Here is the relevant create table instruction, so this tells you the 2 fields in the table as Mark Crossley created it:
CREATE TABLE sqlite_sequence (`name` TEXT, `seq` TEXT)
