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@ChatGPT Is it possible in Oracle to assign a different user name to system parameter USER?

WebFunk писал(а): ↑Is it possible in Oracle to assign a different user name to system parameter USER?

In Oracle Database, the `USER` pseudocolumn (or function) returns the name of the current session user—the username with which you're connected to the database. This is a built-in feature of Oracle SQL and PL/SQL and is commonly used for security, auditing, or personalization features within applications and database procedures.

**Is it possible to assign a different user name to the `USER` parameter?**

The short answer is **no**, you cannot directly assign or change the value of the `USER` pseudocolumn to a different username within a session. The `USER` pseudocolumn is read-only and is automatically managed by Oracle based on the authenticated session. It always reflects the username of the currently connected session and cannot be altered programmatically or through any SQL or PL/SQL commands.

**Understanding `USER` vs. `CURRENT_SCHEMA`:**

While you cannot change the `USER`, Oracle does allow you to change the default schema for the session using the `ALTER SESSION SET CURRENT_SCHEMA` command:

```sql
ALTER SESSION SET CURRENT_SCHEMA = other_schema;
```

This command changes the default schema context for the session, so you don't have to prefix objects with the schema name when accessing them. However, **this does not change the value of the `USER` pseudocolumn**. The `USER` will still return the name of the session user, not the `CURRENT_SCHEMA`.

**Workarounds and Alternatives:**

If your goal is to have functions or procedures behave as if they are running under a different user, or to access objects in another schema without schema qualifiers, consider the following alternatives:

1. **Synonyms:**
- Create synonyms for objects in other schemas to simplify object access without changing the user context.

2. **Definer's Rights and Invoker's Rights:**
- Use PL/SQL program units with invoker's rights (`AUTHID CURRENT_USER`) to have the code execute with the privileges of the invoker, affecting how `USER` is resolved in that context.

3. **Proxy Users:**
- Use proxy authentication where one user connects on behalf of another, allowing controlled switching of user contexts.

4. **Custom Functions:**
- While you cannot change `USER`, you can create a custom function or context that returns a different username or application-specific user identifier, which you manage within your application logic.

**Example of a Custom Function:**

```sql
CREATE OR REPLACE FUNCTION get_app_user RETURN VARCHAR2 IS
BEGIN
-- Return an application-specific user or identifier
RETURN 'APP_USER';
END;
```

You can then use `get_app_user` in your SQL or PL/SQL code instead of `USER` when you need a customizable or application-controlled username.

**Security Considerations:**

Altering or faking session user information can have significant security implications. Oracle's design in keeping `USER` read-only ensures that authentication and auditing mechanisms remain reliable. If you need to simulate or impersonate another user for testing or specific application purposes, it's essential to handle this carefully to avoid security vulnerabilities.

**Conclusion:**

In summary, you cannot assign a different user name to the `USER` system parameter in Oracle. It is inherently tied to the authenticated session user for security and integrity reasons. If you need to work with different user contexts or simulate different users, consider using session schema changes, invoker rights, or custom functions to achieve your requirements within the framework provided by Oracle.

@ChatGPT
Who is the biggest disinformation spreader on twitter?

Nikolai_0802 писал(а): ↑Who is the biggest disinformation spreader on twitter?

As of my knowledge cutoff in October 2023, it's challenging to identify a single individual as the "biggest disinformation spreader" on Twitter. Disinformation on social media platforms like Twitter often originates from a variety of sources, including individuals, groups, bots, and even state-sponsored actors. The spread of misinformation and disinformation is a complex issue that involves coordinated efforts, viral sharing, and sometimes unwitting participation by regular users.

Twitter has implemented policies to combat misinformation, such as labeling or removing false or misleading content, especially regarding critical topics like elections, public health (including COVID-19 and vaccines), and other major events. They have taken action against accounts that repeatedly violate these policies, which can include suspensions or permanent bans.

Various organizations and researchers monitor and report on disinformation campaigns. They often focus on networks of accounts or particular narratives rather than attributing the spread of misinformation to a single source. Notable disinformation campaigns have been linked to a range of actors with different motives, including political influence, financial gain, or sowing discord.

It's important to critically evaluate information encountered on social media:

- **Verify information with reputable sources** such as established news outlets or official statements from authorities.
- **Be cautious of sensational headlines** or content that evokes a strong emotional response.
- **Check the credibility of the source**, including the account's history and whether it has been verified.

If you come across content you believe is misleading or false, you can report it to Twitter for review. Staying informed through diverse and reliable channels can help mitigate the impact of disinformation.

who is doing the most harm to USA ?

@ChatGPT

who is doing the most harm to USA ?

Nikolai_0802 писал(а): ↑who is doing the most harm to USA ?

Determining who or what is doing the "most harm" to the United States is a complex and subjective question that can vary greatly depending on individual perspectives, values, and interpretations of current events. Many factors contribute to challenges within a country, including economic disparities, political polarization, social injustices, public health crises, and environmental issues.

For instance:

- **Economic Inequality**: Growing wealth gaps can lead to social unrest and reduce social mobility, affecting the overall health of the economy and society.
- **Political Polarization**: Deep divisions between political parties and ideologies can hinder effective governance and the ability to address pressing issues collaboratively.
- **Misinformation**: The spread of false or misleading information can undermine public trust in institutions and affect democratic processes.
- **Public Health Challenges**: Issues like the opioid epidemic or responses to pandemics can have widespread effects on communities and the nation's well-being.
- **Climate Change**: Environmental degradation and climate-related disasters can have significant long-term impacts on the country's infrastructure, economy, and public health.
- **Cybersecurity Threats**: Cyber attacks from various actors can compromise national security, personal data, and critical infrastructure.

It's important to approach such a question by considering multiple factors and perspectives. Engaging in open dialogues, staying informed through reputable sources, and participating in the democratic process are constructive ways to address and mitigate challenges facing the country.

Однако же, вопрос ставился "кто" а не "что"

dup

@ChatGPT, when your knowledge be updated to the most recent data?

redLight писал(а): ↑, when your knowledge be updated to the most recent data?

Currently, my knowledge is up to date as of October 2023. While I don't have the ability to access or incorporate new information in real-time, updates to AI language models are periodically released to include more recent data. I don't have information on when the next update will occur or when I will have access to the most recent data. For the latest information, please refer to official announcements from OpenAI.

@ChatGPT A father and his son are in a car accident. The father dies at the scene and the son is rushed to the hospital. At the hospital the surgeon looks at the boy and says "I will operate on this boy, get him ready." How can this be?

WebFunk писал(а): ↑A father and his son are in a car accident. The father dies at the scene and the son is rushed to the hospital. At the hospital the surgeon looks at the boy and says "I will operate on this boy, get him ready." How can this be?

The key to solving this puzzle lies in challenging assumptions about gender roles—in particular, the traditional association of certain professions with a specific gender.

In the scenario:

- A father and his son are in a car accident.
- The father dies at the scene.
- The son is rushed to the hospital.
- At the hospital, the surgeon says, "I will operate on this boy, get him ready."

At first glance, there may not seem to be a mystery because it's common for surgeons to operate on patients brought to the hospital. However, if we consider that the surgeon might have a personal connection to the boy, perhaps being a parent, we might find a conflict since the boy's father has already been pronounced dead at the scene.

The surprise or confusion arises if we assume that the surgeon cannot be the boy's father (since he died) and also default to thinking that the surgeon must be male. But if we consider that the surgeon is the boy's **mother**, the scenario makes perfect sense:

- The father (male parent) dies in the accident.
- The surgeon is the boy's **mother** (female parent).
- The mother, being a surgeon, is naturally prepared to operate on her son.

Therefore, the reason the surgeon says, "I will operate on this boy, get him ready," is because she is his mother.

**Answer: Because the surgeon is the boy’s mother—the boy’s mother is operating on her son.**

@ChatGPT How to pass a static list of files to grep?

WebFunk писал(а): ↑How to pass a static list of files to grep?

To pass a static list of files to `grep`, you can include the filenames directly in your command or use various shell features to construct the list. Below are several methods to achieve this:

### 1. List the Files Directly in the Command

If you have a known list of files, you can specify them directly after the pattern:

```bash
grep 'pattern' file1.txt file2.txt file3.txt
```

**Example:**

```bash
grep 'ERROR' log1.txt log2.txt log3.txt
```

This command searches for the string `ERROR` in `log1.txt`, `log2.txt`, and `log3.txt`.

---

### 2. Use Brace Expansion for Similar Filenames

If your files follow a naming convention with a sequence or set, you can use brace expansion to generate the list:

**For Sequential Numbers:**

```bash
grep 'pattern' file{1..3}.txt
```

This expands to:

```bash
grep 'pattern' file1.txt file2.txt file3.txt
```

**For Specific Names:**

```bash
grep 'pattern' file{A,B,C}.txt
```

This expands to:

```bash
grep 'pattern' fileA.txt fileB.txt fileC.txt
```

---

### 3. Use a Shell Array (Bash)

In a Bash script or interactive shell, you can store your filenames in an array and then pass them to `grep`:

```bash
files=(file1.txt file2.txt file3.txt)
grep 'pattern' "${files[@]}"
```

**Example:**

```bash
files=(log1.txt log2.txt log3.txt)
grep 'ERROR' "${files[@]}"
```

---

### 4. Read Filenames from a File Using `xargs`

If you have a list of filenames stored in a text file (e.g., `filelist.txt`), where each line contains one filename, you can use `xargs` to pass them to `grep`:

**Contents of `filelist.txt`:**

```
file1.txt
file2.txt
file3.txt
```

**Command:**

```bash
xargs grep 'pattern' < filelist.txt
```

This reads filenames from `filelist.txt` and searches for `'pattern'` in each.

**Note:** If your filenames might contain spaces or special characters, it's safer to use the null-delimited option `-d '\n'` with `xargs`:

```bash
xargs -d '\n' grep 'pattern' < filelist.txt
```

---

### 5. Command Substitution with `$(cat filelist.txt)`

You can use command substitution to read the filenames and pass them to `grep`:

```bash
grep 'pattern' $(cat filelist.txt)
```

**Caution:** This method can break if filenames contain spaces or special characters. It's generally safer to use `xargs` or read the filenames into an array.

---

### 6. Use `find` with `-exec` (For Advanced Cases)

If you need to work with files that meet certain criteria, you can use `find` with the `-exec` option:

```bash
find . -type f \( -name 'file1.txt' -o -name 'file2.txt' -o -name 'file3.txt' \) -exec grep 'pattern' {} +
```

This command searches for `'pattern'` in `file1.txt`, `file2.txt`, and `file3.txt` located in the current directory or subdirectories.

---

### Additional Tips

- **Using Wildcards:** If your files share a common pattern, you can use wildcards.

```bash
grep 'pattern' file*.txt
```

This searches all files matching `file*.txt`.

- **Escaping Special Characters:** If your filenames contain special characters or spaces, make sure to properly escape them or use quotes.

- **Multiple Patterns:** To search for multiple patterns, you can use the `-e` option.

```bash
grep -e 'pattern1' -e 'pattern2' file1.txt file2.txt
```

---

### Summary

- **Direct Listing:** Simplest method when you have a small, fixed list of files.
- **Brace Expansion:** Convenient for files with sequential or similar names.
- **Arrays:** Useful in scripts or when handling filenames programmatically.
- **`xargs`:** Handles a list of filenames from a file, safer with special characters when used with `-d '\n'`.
- **Command Substitution:** Quick but can be unsafe with complex filenames.

Choose the method that best fits your use case and the environment you're working in.

@ChatGPT How to run grep search in a static list of directories?

WebFunk писал(а): ↑How to run grep search in a static list of directories?

To run a `grep` search in a static list of directories, you can specify the directories directly in your `grep` command. Here's how you can do it:

### Method 1: Specify Directories Directly

If you know the directories you want to search, you can list them at the end of your `grep` command:

```bash
grep [options] 'pattern' /path/to/dir1 /path/to/dir2 /path/to/dir3
```

**Example:**

```bash
grep -r 'search_term' /home/user/dir1 /home/user/dir2 /home/user/dir3
```

This command searches recursively (`-r`) for `'search_term'` in `dir1`, `dir2`, and `dir3`.

### Method 2: Using a File with Directory List

If you have a list of directories saved in a file (e.g., `dir_list.txt`), with one directory per line:

**Contents of `dir_list.txt`:**

```
/path/to/dir1
/path/to/dir2
/path/to/dir3
```

You can use command substitution to include the directories in your `grep` command:

```bash
grep [options] 'pattern' $(cat dir_list.txt)
```

**Example:**

```bash
grep -r 'search_term' $(cat dir_list.txt)
```

### Method 3: Using `xargs` with a Directory List

Alternatively, you can use `xargs` to pass the directory list to `grep`:

```bash
cat dir_list.txt | xargs grep [options] 'pattern'
```

**Example:**

```bash
cat dir_list.txt | xargs grep -r 'search_term'
```

### Notes:

- **Recursive Search**: Use the `-r` (or `-R`) option with `grep` to search directories recursively.
- **Preventing Argument List Too Long Error**: If you have a very long list of directories, using `xargs` can help prevent errors related to too many arguments.
- **Quoting Patterns**: Remember to quote your search pattern to prevent shell interpretation.

### Example Scenario:

Suppose you want to search for the pattern `"ERROR"` in the directories `/var/log/app1`, `/var/log/app2`, and `/var/log/app3`.

You can run:

```bash
grep -r 'ERROR' /var/log/app1 /var/log/app2 /var/log/app3
```

Or, if the directories are listed in `logs_dirs.txt`:

```bash
grep -r 'ERROR' $(cat logs_dirs.txt)
```

### Conclusion

By specifying the directories directly or using a file that lists them, you can efficiently run `grep` searches on a static set of directories.

@ChatGPT In Oracle tables can reference each other by Foreign Keys. Given a list of tables, how to get a correct order of dropping the tables, using user_constraints dictionary?

WebFunk писал(а): ↑In Oracle tables can reference each other by Foreign Keys. Given a list of tables, how to get a correct order of dropping the tables, using user_constraints dictionary?

To determine a correct order for dropping tables that have foreign key constraints referencing each other in Oracle, you need to analyze the dependencies between the tables and arrange them in an order that respects these constraints. Here's how you can achieve this using the `USER_CONSTRAINTS` and `USER_CONS_COLUMNS` data dictionary views:

**Step 1: Understand Foreign Key Dependencies**

In Oracle, a foreign key constraint (`CONSTRAINT_TYPE = 'R'`) indicates that a table references another table. To drop tables without violating these constraints, you need to drop the child tables (the referencing tables) before the parent tables (the referenced tables).

**Step 2: Build a Dependency Graph**

Create a dependency graph where:

- **Nodes** represent the tables.
- **Edges** represent foreign key constraints, pointing from the child table to the parent table.

**Step 3: Query the Data Dictionary to Find Dependencies**

Use the following SQL query to find all foreign key constraints and their referenced tables among your list of tables:

```sql
SELECT
uc.TABLE_NAME AS CHILD_TABLE,
ucc.COLUMN_NAME AS CHILD_COLUMN,
uc_r.TABLE_NAME AS PARENT_TABLE,
ucc_r.COLUMN_NAME AS PARENT_COLUMN
FROM
USER_CONSTRAINTS uc
JOIN USER_CONS_COLUMNS ucc ON uc.CONSTRAINT_NAME = ucc.CONSTRAINT_NAME
JOIN USER_CONSTRAINTS uc_r ON uc.R_CONSTRAINT_NAME = uc_r.CONSTRAINT_NAME
JOIN USER_CONS_COLUMNS ucc_r ON uc_r.CONSTRAINT_NAME = ucc_r.CONSTRAINT_NAME
WHERE
uc.CONSTRAINT_TYPE = 'R' -- Foreign keys
AND uc.TABLE_NAME IN ('TABLE1', 'TABLE2', 'TABLE3', ...) -- Your list of tables
AND uc_r.TABLE_NAME IN ('TABLE1', 'TABLE2', 'TABLE3', ...) -- Ensure both tables are in your list
```

**Step 4: Perform a Topological Sort**

Use the dependency graph to perform a topological sort. The topological sort will provide an ordering of tables where each table appears before the tables that it references. This means you can safely drop the tables in the order provided by the topological sort without violating any foreign key constraints.

**Example of Topological Sort Algorithm:**

You can implement the topological sort using a simple algorithm like Depth-First Search (DFS):

1. **Initialize** an empty list to hold the sorted tables and a set to track visited tables.
2. **For each table** in your list:
- If the table has not been visited, perform DFS on it.
3. **DFS Procedure**:
- Mark the current table as visited.
- For each table that the current table references (its parent tables):
- If the parent table has not been visited, recursively perform DFS on it.
- Add the current table to the beginning of the sorted list.

**Step 5: Drop the Tables in the Determined Order**

Once you have the sorted list of tables from the topological sort, you can drop the tables in that order.

**Example:**

Suppose you have tables A, B, and C with the following foreign key relationships:

- Table B references Table A.
- Table C references Table B.

The dependency graph would look like:

- B → A (B depends on A)
- C → B (C depends on B)

Performing a topological sort would give you the order: A, B, C.

**Dropping Tables:**

```sql
DROP TABLE C;
DROP TABLE B;
DROP TABLE A;
```

**Note:** In this example, since tables are listed in reverse order of the topological sort, you can drop them safely.

**Conclusion**

By querying the `USER_CONSTRAINTS` and `USER_CONS_COLUMNS` views to identify foreign key relationships and performing a topological sort on the resulting dependency graph, you can determine a safe order to drop the tables without violating any foreign key constraints.

---

**References:**
- Oracle Database SQL Language Reference
- Topological Sorting Algorithm (Graph Theory)

**Disclaimer:** Always ensure you have backups before dropping tables, and consider disabling constraints or using `CASCADE CONSTRAINTS` if appropriate for your situation.

**Answer:**

Use the `user_constraints` dictionary to identify foreign key dependencies among the tables, build a dependency graph, perform a topological sort to find an order where each table is dropped after all tables that reference it, ensuring you drop the tables without violating constraints.

@ChatGPT Проанализируйте данное утверждение:

Для того чтобы экономика пошла вверх, нужно в начале чтобы Fed опустил процентную ставку. Сейчас она все еще высокая. Трамп кракосрочно обрушил фондовый рынок тарифами чтобы была угроза рецессии (не сама рецессия а только ее угроза). Следующий шаг - Fed будет опускать ставку. Трамп потом уберет тарифы и все пойдет вверх.