Gold Study Guide Word Doc Flashcards
(41 cards)
API Server
A single threaded process that handles REST API calls
Application Server
Handles the web application, supports browsing and searching.
App server handles authentication
This process is multi-threaded
Backgrounder
A single threaded process that executes server tasks, including extract refreshes, ‘Run Now’ tasks, and tasks initiated from tabcmd
Cache Server
Query cache shared across all Tableau processes in a cluster. Used by Backgrounder, Data Server, and VizQL
Cluster Controller
Responsible for monitoring various components, detecting failures, and executing failover when needed
Coordination Service
In distributed installations, responsible for ensuring there is a quorum for making decisions during failover
Data Engine
Loads data extracts into queries and memory
Data Server
Manages connections to Tableau Server data sources
File Store
Automatically replicates extracts across data engine nodes
Repository
Tableau Server database, stores workbook and user metadata.
Stores Application Data, File Data, TWBs and TDSs
Based on PostgresSQL
Meta-Data and Application Data can be queried and reported on in Tableau
Search & Browse
Handles fast search, filter, retrieval , and display of content metadata on the server. Queries meta-data from TWBs and TDSs. Based on Apache SolR
VizQL Server
Loads and renders views, computes and executes queries
Explain the following: Count, Sum, Average, Minimum, Maximum
Count - the number of values. Sum - the sum of values. Average- the average of values. Minimum - the minimum value. Maximum- max value
First Quartile, Median, Third Quartile
The values observed at the 25th, 50th, and 75th percentiles
Standard Deviation
Measures the amount of dispersion or variation in a set of values
What % of the data are within 1, 2, and 3 standard deviations?
1 - 68% of the data. 2 - 95% of the data. 3 - 99.7% of the data
Skewness
Measures the asymmetry of the distribution of values around the mean. Think of this as whether the curve is weighted to the left (positive skew) or the right (negative skew)
Excess kurtosis
Kurtosis is a descriptor of the shape of a curve. It’s tall and skinny (positive kurtosis) or flat and wide (negative kurtosis)
What are the fields in the “describe trend model” dialog?
Model formula Number of modeled observations Number of filtered observations Model degrees of freedom Residual degrees of freedom (DF) SSE (sum squared error) MSE (mean squared error) R-squared Standard error p-value (significance) Analysis of variance (ANOVA) table Individual trend lines table Terms Value P-value
Model formula
the formula for the full trend line model. The formula reflects whether you have specified to exclude factors from the model.
Number of modeled observations
the number of rows used in the view
Number of filtered observations
the number of observations excluded from the model
Model degrees of freedom
the number of parameters needed to completely specify the model. Linear, logarithmic, and exponential trends have model degrees of freedom of 2. Polynomial trends have model degrees of freedom of 1 plus the degree of the polynomial. For example a cubic trend has model degrees of freedom of 4, since we need parameters for the cubed, squared, linear and constant terms.
Residual degrees of freedom (DF)
for a fixed model, this value is defined as the number of observations minus the number of parameters estimated in the model.